We are not in the age of victorian psychiatry. We are in an era of modern neuroscience and psychiatry. You seem stuck in the past about that. There's major advances in neuro science that allows for imaging of the brain's activity. AIUI many of those disorders that traditionally have been treated as artificial pseudo disorders, of which ADHD has traditionally been seen, can be physically observed through modern neuroscience's major advances over the last 5 or 10 years. It's revelatory like xrays once were.
BTW I grew up in times where ADD was first proposed and the medical and educational establishment just wrote it off as apologising for bad behaviour of children, bad parenting or both. Right now it's very much accepted and studied.
There's been enough research to believe it's a theory that holds under scrutiny. It's not labels it's a diagnosis as valid as one for cataracts indeed more valid than many accepted conditions like IBS (which as a sufferer I know it's just a label a gp puts on a range of issues to fob patients off with over the counter medicines to ease individual symptoms rather than trying to work out what it really is).
As to your other points, which AFAIK seems to be about general public 's acceptance or not of it and the resulting attitude to people identified as having it. That's all part of the problem. Mental health, of which I believe ASD and ADHD comes under, needs acceptance and understanding. Calling it a label or a label of convenience it whatever you're saying isn't that IMHO.
I suggest that the categories of the US journal and other psychiatric tomes are not so much made-up as very imprecise, confused and perhaps even inappropriate to describe as medical conditions or illnesses requiring treatment.
Imprecise? Confused? I suspect that's an issue with the state of modern understanding of such disorders. If we're still trying to understand a condition or disorder of the brain then that's really not an issue with the disorder but the issue with where we are in the understanding of the mind. It's like we're only just looking into it because the technology to image and study brain activity is barely a couple of decades old, if that. I once heard it described in a succinct way along the lines of comparing it to another established branch of medicine but centuries back. We're really just starting to crawl in the study of the brain.
As to treatment, well what is treatment when you can't define causes? You can't treat you manage. Just like migraines, epilepsy (I guess) and IBS (whatever that really is). One way might be a Ritalin type of medication for ADHD or CBT / other so called talking treatments. I understand they can work well once the level is sorted. It's at least a potential help but not a real treatment.
Personally I feel the issue is that having broad and imprecise labels to identify "a spectrum" of quite variegated behaviours can cause more problems than it solves. It isn't only others who use such labels to stereotype then villify, condemn or discriminate against those so-labelled. It can be a self-defeating acceptance by a person so-diagnosed that they are abnormal and therefore inadequate, at fault, ill, disabled or otherwise incapable. Acceptance of the label and the notion that it's "a mental disability" is a sort of self-fulfilling prophecy that "I won't be able to cope".
OK, broad and imprecise. IMHO disorders such as ADHD are very broad. Why? I don't know and I doubt many do of any. It's cause(s) aren't known. That's always going to be the case until more is known about it. At what point was a running nose connected to a cough and called a cold? What symptoms get lumped together as one condition only to be found out as another. I once thought I was unlucky getting cold after cold but it was simply an allergic reaction to one or more allergens. Until we understand disorders better they will be broad. Who knows ADHD might end up being co-morbid disorders lik3 ASD and ADHD can be. Bi polar disorder too is co morbid.
Others using such diagnoses as ADHD or ASD to criticise or vilify the person isn't the disorders fault it's simply the prejudice of the person who uses it against the person with that diagnosis. Saying the diagnosis is problematic because it divides that person out for negative response is a big problem. Is it not apologising prejudice? Serious question. Writing off the diagnosis because of other's reaction to it. Is that what you are saying?
As to self fulfilling prophecy. Oh dear. Anyone who has gone through the trials of getting a diagnosis in the modern NHS is not someone for whom a label for their disorder will cause it to suddenly make it a problem. For a start you're not going to go through that long drawn out process unless you already have a problem. It's there already. Can I suggest you read some of the numerous posts on getting a diagnosis on any add/ADHD forum. It might help you understand the difficulties of getting help and the nature of the problems faced. Plus the results of getting that diagnosis and help.
Perhaps my view is totally wrong here but I for one know I have a problem. I've made a move towards diagnosis and two medical people so far think I have very good indications of ADHD and that I have a problem that is worthy of investigation using the limited resources of the nhs. First step gp, second step pointless phone consult by depression service. Third step would be gp again. It might get diagnosed in two years of back and forth between gp and various NHS mental health services. Eventually I might get referred to a centre in London which I heard might no longer be dealing sun nhs patients or possibly there's a Scottish centre looking into it. More likely I'll get told it's private diagnosis or nothing.
My point is the diagnosis and receipt of what you call a label is a long drawn out battle to get. You will never do that unless you feel your problem is worse. That's the decision only the person can make themselves with good advice (currently only available informally from other people with such a disorder on a few forums. Once you've made that decision you're really not going to fulfil any prophesy about not coping because you're already there.
BTW labels and mistreatment from others over such disorders is prejudice and should be condemned. Disability. You could argue the same for wheelchair users or the blind. Is calling someone with a disabling condition or disorder disabled right. If you dispute ADHD as disabling then that's possibly it not understanding its severity or potential for being severe. Might be easier with ASD because someone with severe autism is not able to fully function in modern, society at the same level as someone not on the ASD spectrum.
BTW my use of medical conditions isn't equating then exactly I'm only trying to make points about diagnosis and acceptance. The process of diagnosis of asd or ADHD is at its core a similar process as diagnosing medical conditions in that you look at the symptoms and history of the person. Of course under current neuro science the idea of a diagnosis and potential for managing symptoms is the best to be hoped for.
Anyway I doubt I'll change the view of someone who has the view a medical doctor who has specialised in psychiatry is comparable in any way to an astrologer. They're not the modern day version of a blood letter physician. It's a genuine medical specialism these days and is increasingly being backed up with neuroscience.
. If I sound "blunt" in my posts, please be understanding : I am not perfect. Thank you. Visit 
