Originally Posted by
Maelochs
This is not a "jewels vs. tools" thing, it is about properly caring for your tools. Riding in the rain eats bikes, not because of rust, but because fine grit gets pushed into every bearing surface and juncture, from the bottom bracket to every link of the chain, and then grinds away at all your mechanicals. Also, you don't want to be swapping fenders on and off your regular ride after every rainy day.
Plus, it is a reason to own yet another bike (n+1 as was noted above.)
No difficult concepts there.
I have yet to experience a bike getting "eaten" by riding in the rain. Yeah, it picks up a lot of sand. The answer to this problem is cleaning and maintaining the bike, which you need to do with a rain bike anyway unless you enjoy the sound of grinding sand. I've been riding my steel race bike in rain and on wet, salty winter roads for four years now and it has yet to be eaten. I'm not necessarily opposed to the idea of a rain bike if you want to have one, but I do think it's a false economy. Taking care of your tools is cheaper than buying more tools to just abuse.