My personal opinion is that anyone who is really concerned about their finances and wants to succeed in investing - should not follow and do what anyone tweets on the Internet. Or at least not before he did his own research on the information in question from this tweet.
People who have a huge number of followers and have a lot of influence over the masses usually do everything for their own benefit and manipulate people, and cryptocurrencies are one of the things that is influenced by a hell of a lot of speculation and manipulation.
We can't blame people like Elon Musk cause they don't have adequate knowledge about crypto currency, he only believe what he was told or read from an experienced people, we can use the moment before he invested in Bitcoin as example. It was the Microguy CEO that adviced him to and even said that he's just an engineering in one of his tweet but despite that some people still sees his tweet as investment advice and the reason why he believes Bitcoin mining increase fossil fuel usage is because of the hype/fud article he read about Bitcoin.