Why are people calling Bitcoin a religion?

Because they both prey on people by making things up so a few can make money.

Not a religion but for many it has become a cult.

Sure wish I had invested about $100 in 2010.

If bitcoin is a religion then so is the stock market. The current financial establishment hate bitcoin because they can't control it and it allows normal people to participate in commerce on more equal terms

This seems a bit delusional. Bitcoin is every bit as much controlled by the financial establishment as the stock market is. The mere fact that it works differently and has this libertarian ideological backstory doesn't change that reality.

Also, I'm not sure what you mean by equal terms. Anyone can participate in the stock market just as easily as they can in crypto markets. Of course the wealthy have a huge advantage over normal people in stock markets, but they have the same advantage in crypto markets, probably even more so given the volatility in them.

It's not a religion, it's a scam.

Like all speculative investments it requires "faith" that prices will go up. When faith is lost, the religion will crumble.

I think this requires another read of American Gods, maybe Neil Gaiman could come up with a good name for the god of crypto.