They hate it even more when you pass them on a singlespeed... especially when climbing a mountain rode. When turn to say hi as I always do, they normal do respond though.
The funny thing is that in the races I race in there are PRO mountain bike riders, and they are always really friendly about passing. So why is it that the mountain racers who really are the best aren't smug, but the average joe road biker is? Still, I've met a lot of friendly roadies out here, so maybe it's a Midwest thing. We all love to pedal, so why can't we all get along.