Because it is not the people who are aware of cryptocurrencies and their scams that give power to those influencers, it is the masses. People simply just follow those kinds of influencers because of the way they grow the account or their personal brand, and do note that some who partner up with them could simply create a campaign that pleases the masses, for example, free giveaway, freebies, and such kind of things.
So the ones who make a stupid person famous are not the ones who comprehend it.
Some account that was specifically made as scam buster did that, but the rate of those fake influencers are enormous and not all of them are effective. On one hand, there is a people who just can't simply able to protect themselves, no matter what scam scheme they have encountered, with a little twist, they will fall for another one.