The difference is we have made EXCELLENT beers and taste excellent beers all the time. Many of us are "beer snobs" or at least "educated beer folks". We TRY to find flaws and reverse engineer the beer in our heads (ok well I do anyway).
My friend that doesn't know the difference between Irish moss, Centennial hops and Marris Otter grabs a beer because he wants to "catch a buzz" or is thirsty. Most of these folks drink BMC and like to try new beers that I brew. 50% of these type of friends will lie to your face to spare your feelings if they do not like your beer and will drink it anyways because it is free...
This does not even take into account the "guitarist theory". Say you are playing a medium concert all by yourself. Let's say you are pretty darn good. 1/4 the way into the show the highest string on your guitar breaks, you do not have a spare with you and do not get paid until after the show.
You can A) Stop playing, put both hands on your head, yell a profanity followed by "shows over" and not get paid...or B) You suck it up, yank the bad string off without missing a beat, finish the show, smash the guitar, light it on fire Hendrix style and collect a fat check that covers the guitar anyways...same goes for beer. Presentation is just as important as reality, sometimes more so (BMC has done this forever)...to my friends/fans I AM a great brewer and make great beer.
True story: I have a batch of this not so good yellow, infected garbage that I was going to dump. I let it sit hoping it would sour and it never really did. A month passes and a friend that has a Luau party every year asks if I can brew up something for the party. 2 pineapples, 12oz of toasted coconut and 1oz of homemade vanilla extract later and I have a beer that I have named Luau Brau Special Reserve. It really is a lot better than it was but I also have some that is a lower gravity just pineapple beer that has a sharp astringent/earthy off taste at the end. (It was the pineapple/fruit that caused the infection but the beer has always tasted odd to me.)
I am going to bet everyone at the party tells me how fantastic it is. I do suspect a few folks to say "not my deal" and not drink it but I suspect I will be coming home with empty kegs at the end of the day.