Some people like them, and some don't. Those who don't do so for various reasons.

I won't go into the economic arguments. Or even the moral ones.

I'll just observer that some people wish to be slaves. You may think that's harsh, but I think it's just an accurate observation. Some people have a will to servitude. They wish to find someone or something to obey.

And if they're going to obey, you damn well will too. Whether one is a slave to God, The Church, Society, or The Party probably is largely a matter of happenstance, of where you happened to grow up . Some people want to live in a world of obedience.

A market transaction means someone, somewhere got to make their own choice, to decide for themselves, instead of merely obey. That's why some people don't like markets - they don't want people free to chose.