They do it just because they can, to boost their stupid egos.
May be his ego is making him to tweet. But as you mentioned I doubt whether he is bothered if anyone follows him or not.
However, even if we're having a loss right now, more people are stronger than a few dumb billionaires and I'm sure BTC will come more powerful than before.
The market is over $50k and you think that it is not enough. It is good too see corrections once in a while and no one can manipulate the market for a much longer time.
The history won't let Mr. Snake Musk escape with zero consequences.
what do you think will be the consequences, zero as he never leaked any insider information and he was doing these sort of market influencing tweets for the past few years and now he is more tweeting about cryptocurrency market and that is the only difference.