Loads of them down here. You live in flat Essex BFB, where MTBs were the dominant mode of cycle transport when I was an Essex lad. In the hilly areas people who like to cycle soon cotton on to the fact that a lightweight roadbike is mush easier to haul around than a heavy full susser.
I was out on my road bike on Sunday morning in the pi**ing rain and howling gales! Although it'll be the MTB on Wednesday night. Riding at night I'd rather be travelling slower and land in a gorse bush or muddy puddle than hit a concrete kerb or metal car, even if the chances of coming off are much higher when MTBing.
I was out in the rain on Sunday on the road bike - (only 10 miles quick spin as I had to go out) after yet another week commuting on the mtb...sooo nice to get out on a light, fast, responsive bike...saw a few others as well (roadies that is)
Funny you should say that, I had been thinking the same thing, then today I saw one. He had the helmet, lycra, dark specs and funny shoes. Still, on second thoughts, perhaps he wasn't a roadie, this guy gave a friendly greeting as he passed.