Why drop bars if you are not racing. Why group rides if you are not training for a race? The UCI definition has destroyed progress in the design and popularity of bicycles as transport
I find myself in disagreement with some of your points.
Drop bars off multiple comfortable hand positions for different conditions and in some ways offer versatility
beyond what is needed for racing, other bars also offer alternatives (butterfly, flat, north road, whatever takes your fancy) and they are simply that, alternatives, and often very personal so I do not think drop bars should be confined to 'racing' bikes only.
Group rides can be both very sociable, and efficient, and people can train for 'non race' events as well as for personal improvement, they are certainly not only for race training. Group riding does come with responsibility to other memebers of the group though so behaviour and bike equipment choice is relevant.
I think it has much more to do with people aspiring to, and being lead by the
image of racing bicycles rather than practicalities, but the UCI have no hold on practical bicycles and I think blaming them for the public's continued aspiration to racing models is unfair. So it's down to a combination of manufacturers and shops selling an image that is incompatible with reality, and customers not willing to compromise on that image, many highly practical bicycles are available, and it's not the UCI that stops people buying them, nor has the UCI hindered their development, it might be fair to say the UCI has stifled development in racing, but that's a different kettle of fish entirely and comes with it's own arguments as to whether they should or not.
It's been said time and time again, but practical, fully equipped bicycles in the UK are a hard sell, and its mostly an image and aspiration thing, the non seasoned cyclist buying a bike for leisure and sport is lead by the image of sporty bikes and the lure of 'performance' and so the manufacturers and shops cater to that. You only have to look across the channel to see a shift towards more practical bikes, and more markedly so in Germany and the Netherlands, it's always amusing when a European customer enters a UK bike shop and is perplexed as to why none of the bikes have racks, guards and lights by default.
Having said all that I think the cycle to work scheme and general (slight) increase in utility and transport cycling in recent years is prompting a gradual shift in some areas. There are a lot of general purpose bikes appearing now which are getting closer and closer to ideal, but they're still a hard sell to someone who doesn't already cycle a lot.
My wife recently bought a new commuter, we went to the LBS for her to have a look and test some models out, she's a seasoned cyclist and knew what she wanted as he previous commuter had some shortcomings that she wanted to address, namely lack of clearance for tyres >25c, no mudguard clearances and rim brakes which she was fed up of feeding pads and rims to after all-weather commuting for several years. But as soon as she said road commuter she was pushed towards some lightweight carbon and aluminium models from Spesh and Trek in both flat and drop bar guises, she said she would need to add racks and guards and while it would have been possible to add them they were not ideally suited. She did try them but was not taken with any of them and eventually settled on a Specialized Source, which I'm actually pretty impressed with as a general purpose commuter. Alu frame which is sensibly light but well built, decently long wheelbase with longish stays for pannier room and stability, sensibly robust 8speed transmission with a mid-compact triple, hydraulic discs and 35c tyres. It even came equipped with guards and racks of adequate quality (although they'll probably be replaced in a couple of years) all for < £500. It has flat bars, but would work equally well with drops, it will only ever be used on roads and paths, it's not an 'off road bike' but she still doesn't call it her 'road bike' as that's what her lightweight drop bar bike is even though that won't be raced.
Anyway, to answer OP, it depends on the perception of the person as much as anything, I consider 'road bike' to be a contraction of 'road racing bike' and as such it means a racing or primarily performance oriented bike to me, but I can see how it would just as easily mean 'not an MTB' to anyone who grew up through the BMX and MTB booms.