There are two kind of communists from what I've seen. The useful idiots and true believers who unironically believe things like "real communism has never been tried before" an think that they're one more attempt away from a utopia.
The other kind you mentioned are the tankies. They see the old "boot and face" analogy and fantasize that they'll be the boot. They're usually the first against the wall if they get their way.
This is easy to understand once you realize that every single person left of center is a Bolshevik.
They all dream of becoming a commissar. They desperately want their hands around your throat.
There are two kind of communists from what I've seen. The useful idiots and true believers who unironically believe things like "real communism has never been tried before" an think that they're one more attempt away from a utopia.
The other kind you mentioned are the tankies. They see the old "boot and face" analogy and fantasize that they'll be the boot. They're usually the first against the wall if they get their way.
Third kind you missed - the sociopaths at the top. First two are both varieties of useful idiots to the power at any cost types that use them.