It is interesting to observe people engage in machismo when something (a new sport, say) they thought was theirs and they were the only one doing it suddenly goes mainstream.
They feel like they have to talk and act tough in order to defend TO THEMSELVES having that thing be part of their identity.
Usually those people show up and get cut down to size very quickly.
They also tend to always criticize whoever or whatever org popularized it (because of course, they could do it better…and…that's why they didn't).
In the case of music or a band many times the fan will behave like a jilted lover and turn against what they had loved for 'selling out'.
These are people who actually despise success because they are not willing, either consciously or subconsciously, to put in what is necessary to either create or take something existing and become successful at it.
And it is much easier to simply criticize, than it is to learn, emulate, reverse engineer, practice a skill, or do what is necessary to become the industry standard of success.