That's because initially Medium offered money for the most claps. Marketers found it easy to game the system (as did many others). They all clapped for each other even without reading, and so they made lots of money. And as everybody is desperate for money these days, people will read anything on how to make money - especially if they don't earn much. There are many of those.

People also assume that learning their ABCS at school is the same thing as someone who writes to a professional, publishable standard. That's like saying that dancing in a club is the same thing as dancing the lead in a ballet performance.

Not even remotely the same.