Case in point, who in their right mind thought a bunch of self proclaimed smooth brains would hold and not panic against ladder attacks and FUDs? The smooth brains have been in the game as much, they have seen their capital dropping to 0 more than the HedgeFunds are accustomed to losing at their own game.
A hedge fund with capital and influence, capable of controlling the narrative, could and tried to decide the outcome of their bet based on their bet, we saw this with TSLA as well. They believed, like most people, that GME would go bankrupt, they didn't consider the bull case [1] because things had been going down for so long, but GME's revenue is periodic, bringing us back to the fallacy. Things are how they are until they are not, and the inability to adapt due to logical fallacies becomes evident. There's a reason why reasonable people in WSB suggest an investor should know both cases by heart, if you can not afford to control the narrative, you can not direct the behavior of the market.
[1] www.gmedd.com
I do agree that fundamentals (for whatever it means) are not sufficient for success. In the end of the day, investments are based on speculations about the future. The reason the fundamentals matter is that they provide some guidance for your speculations. The basis which you can build your narrative upon. Sometimes they can mislead you, often things happen you missed or couldn't predict (e.g., a pandemic), etc.
Finally, I also agree (if that's what you meant) that some narratives people follow are not based on fundamentals, but rather based on their biases or whatever someone else may have told them. But if you ask me such investments fail more often than not.
That is the argument, the hedge funds made a bet and had already decided the outcome, my argument is simply that they ignored the bull thesis because they had already decided the outcome. They also ignored the possibility of getting royally forked up. If main street figured it out, somebody else could have as well, and Michael Burry did.