But that makes the argument false. A self fulfilling prophecy is argumentative fallacy and is false because what is prophetised allows the wanted effect to come to fruition. Example: B20 cymbals are better, and I have one, and it's better than my B8. This is only true for me, not everyone, so the claim that B20 is better is not a valid argument.
Hahaha I'm not saying I agree with it in principle, just that if manufacturers make most of their best cymbals out of B20, then when people say B20 cYmbAls arE bETer they're probably statistically correct.
When someone asks on a forum like this what cymbals they should upgrade to, there are always a few people who say 'you should buy B20 cymbals because they're the best', which reflects the actual marketplace so you can't really blame them for thinking that...