If we are to be really honest with ourselves, the cause of the recent dip in the market is not because of Elon Musk tweet or because of China ban on crypto (though it added to it). It is because the market has been in an overbought position long enough. Taking Bitcoin for example, the price increased so fast (leaving a price imbalance/void) without any serious retracement or correction. So the market is just correcting itself.
The reason why Elon was blamed is because he was a catalyst to the untimely heavy dump, his tweet like you said hasten things up, to me, i think Elon's tweet have far more effect than that of china banning crypto because in the case of china, many are already use to that hide and seak game, but coming from Elon, and Tesla, it was a big news that cause chaos and immediate panic sell.
You are right. Even though we understand that the market was already overbought and a correction was imminent, the Elon musk tweet kinda accelerated the down move of it and that cannot be overlooked and even considering the way it all played out from his angle. We know the first time he tweeted about buying Bitcoin and accepting it for Tesla payment, Bitcoin pumped upward even though the market was already on uptrend and he got credit for that so he gets the blame for this too.