But companies are legal entities, they can buy, sell and own stuff. They aren't just a collection of people. They can make profit, some huge amounts, and they should pay taxes for that.

The owners of a corp aren't the ones paying tax. The corp has its own balance sheet.

You don't understand that in the US's capitalism corporations are people. That's why they are able to use infinite money to influence elections (because in American CAPITALism, corporations' usage of money equals free speech and you can't limit people' speech). Yes, I agree, it's absolutely insane.

Google "Citizens United v. FEC" Supreme Court decision.

Conveniently, they are people only when it comes to corruption and influence. But not when it comes to rules or punishment (like if a corporation killed people, it should be possible to give it a death sentence).