Can you imagine if the CEO of Ford Motor Company was openly using drugs with wild eyed/slurred speech,
Maybe you can't, but I easily can imagine, because stuff like that happens, always happened, yellow media always enjoyed playing these stories. Your confirmation bias just distorts your vision in that it's somehow unique to Elon Musk.
You have the pieces together for understanding - just apply some common sense and introspection. You correctly point out that Musk is minority shareholder and can be replaced. Now do you really think other shareholders are idiots? Of course not. They are most interested in money - the value of their investment, like professional shareholders always are. They are wiser than you or me.
So
something in your chain of logic must be incorrect because the pieces don't seem to fit, and it's this:
causing the collapse of the share price?
You really serious?

Tesla's stock value during Musk's time is nearly miraculous rise, and pretty sustainable growth despite everyone "knowing" it's only a temporary bubble that will burst "in a year", for... 15 years already? This is an undisputed fact. Now maybe it's not Musk's excellence, maybe someone else would have done
even better job... but given the track record for stock value, replacing Musk with someone else seems like a huge risk. Which is why investors don't want to do it.
And eventually, yellow media cannot affect the outcome of market realities that much. They might run scandal stories about Musk taking drugs, or Musk having wrong political views, and then run another story when stock price drops by 20% 3 weeks later. Then people like you can believe that oh, due to Musk tweeting, now the stock price collapsed. But guess what? You were just being used, lied to. You did not check the stock price yourself, you just read the media, so you missed the fact that stock price rose back again 2 weeks later, and beyond. This is exactly what stock prices do, they fluctuate. Understanding
why is a bit more complicated than yellow media makes it look like.