I may ;have just been lucky, but, I have not had many bad experiences at audio shops. I have seen many customer/shop interactions, including adverse interactions, and in the most cases, I would put "blame" (if that is a fair word) on the customer--many come with strong opinions and are offended by the salesperson who has a different opinion; many seem to come in spoiling for a fight or they come in expecting to be confronted so they are in a defensive frame of mind.
Why wouldn't the salesperson ask questions about a customer's system so that he has a frame of reference and can suggest what should be addressed first; why are some customers so defensive about this type of question? There appears to be so much insecurity among those going into shops. If the salesperson has a strong opinion about what is good sound and what is not, I don't mind this at all, even when that person's opinion differs from mine. I prefer that a shop have a "vision" and perspective rather than one just stocking what is the reviewers' flavor of the month.
At the two shops in my area (Northern Virginia) that I really like--Deja Vu Audio (tube-based electronics and old school speakers and turntables, including their own custom builds) and Command Performance AV (tube and solid state, popular high end brands) visits are fun experiences and not painful high pressure sales experiences. At Deja Vu, the owner has a very strong opinion on what is good and not good sound and is not afraid to tell someone that he thinks a certain piece owned by the customer is crap, but, if you show enough respect by listening to what the store offers for sound, you will be treated with respect in return and you will learn something even if you are not "converted." The people at Command are also generous with their opinions, but are perhaps more diplomatic, and will treat customers fairly.
Go into a shop with a friendly, positive attitude (expect to enjoy the experience, don't go in fearful of being intimidated), treat the salesperson with respect (allow them to speak without confronting every utterance), be honest about what you are looking for (even browsers are welcome in most stores), and shopping in a brick and mortar shop will be fun.