Yes, that has happened to me also, but there are more good shops than bad in my area. One of the shops has a pair of mechanics that are big fans of vintage bikes, they often invite me into the shop area to show me what they're working on and to talk shop. They don't have stock much of the things I typically need, but I try to spend my money there when I buy locally.

I can think of at least 3 shops that have 27" tires, but they're cheap Kendas for the people who are pulling their bikes out of storage for the first time in 20 years.