Lets start from your statement - it is shit. And people paid 70$ for it. No need to go further. Their voices deserve to be heard (since, you know, 70$). And now you say that they shouldn’t have believed the hype as if they are wrong and not the people that overpromised and (not underdelivered but) lied.
There are no twitter stocks, you can’t buy or sell them, and therefore can’t short them, since you need to borrow them to do just that. This could work if Elon had some percent of the company, so other people’s money would enter the equation, but right now it is not possible.