I guess I'm luckier than most. I've got two LBSs that I regularly patronize (one near work, one near home), and they both know and treat me with respect. Of course, when you walk in with a bike that's obviously been tricked for commuting and ridden hard, that might make a difference. My bike's not pretty, but you can tell it gets ridden.
When I first went into the shop near my home to buy a bike, I explained to the clerk why I wanted one and what I wanted to do with it, and he was very helpful. He recommended a couple of models for me, fit me to a couple for some test rides, and explained the differences between them, with some specific recommendations about why one would be a better ride for a clyde than the other.
I doubt that the guys at either shop know my name, but they're all welcoming and very helpful whenever I come in. OTOH, we have lots of shops here in the Seattle area, so if you don't like one for any reason, there's another just down the road. That probably makes a big difference.