I can see his point though......my friends buying audio gear without asking my opinion is like me hiring a carpenter without talking it over with my carpenter friend.....hiring a landscaper without talking it over with my landscaping friend.....because these guys could either do it cheaper, or recommend someone who can do it cheaper and do the same...if not better quality of job, ya know?
Maybe they believe they are old enough to make their own decisions. What may be pleasing to me, may not be pleasing to you, as what may be pleasing to you is not what they want.
Bose is a GREAT example. Take a Bose Wave Radio. Would I pay full price for one, no, because I think for the money there are many good alternatives, but let's say my parents want to buy one. I could go on a 10 minute tirade on why they shouldn't; I have done a few things here.
1st, I have made them feel ignorant and as though their opinion means nothing. They could have researched it and read hundreds of people's reviews saying they are satisfied with it, but smart aleck me supposedly knows better ?
2nd - let's say they do buy something else. Even tho it could be as good or better, there is a good chance they will find something they do not like about it and every time they turn it on, they will wish they bought the Bose.
If someone asks your advice, great, give it to them and explain why, but also explaining to them everyone has different tastes, needs and desires. You are not buying it for you, so as any good salesmen would do, find out exactly what features etc they want and how they plan to use it and explain why you think so and so would be a good choice. People always feel so much better if they feel they are part of the solution instead of being belittled for their ignorance. They are your friends or relatives after all.
If you know someone who is buying but does not ask your opinion, yet know you are really into audio, keep your mouth shut, if they like it, tell them it is great and be a part of their happiness.
Tis what i would do anyway