I seem to have joined the shift from mtb'ing to road riding - nothing to do with it being the new 'niche' (I had no idea it was!), but due to a knee injury making mtb'ing not possible, but road riding OK. At the time, I did see it as 'better than nothing' until I was able to mtb again, but now I do prefer road riding to off-road.
It's got minimum pre-ride faffage - quicker and easier to just grab the bike / water bottle and head out, I've got a huge variety of great road routes straight from the door, no having to sort out transporting bikes in cars or fuel costs, and minimal post-ride cleaning. Plus I love it! Whether that's ambling along chatting to the new lambs, or the satisfaction of sweating to the top of a steep climb, or the letting go of the brakes for a 'I can't believe I'm going this fast' descent.
Couple of downsides - most of my friends are mtb'ers (and don't feel the love for the road), and most of the clubs are race orientated and I'm into it cos I just like road riding / having a bit of a blether / sometimes admiring the scenery and sometimes going as fast as I can / stopping for a panad or a pint. I'd really like to see more 'social' road rides / clubs. Also, it does seem to be a farily competitive and male dominated scene.
But I have found most roadies I meet to be pretty friendly (although I suspect that the group who called out 'allez, allez' at me when I was going at the speed of a snail up the hill might have bee taking the piss a little!)
Oh, and I'm not fat, nor do I have a small willy, so I guess i can get away with wearing lycra