Reddit exists because we give it content. We're the ones bringing value to Reddit. Like any social media, it wouldn't exist without us, the users. Reddit also provides a valuable service as being the host. Reddit is entitled to make some profit off of that.
We contribute content to Reddit for free. Reddit acts as a good host, connects us users together, and makes some money for their work.
But they've been growing increasingly user hostile and greedy. I'm not going to give you free content if you're super hostile to me and other users. Hosting Reddit isn't that expensive, afaik they were already making a profit back when you could buy gold to fund server time? But if you're going all in on ads and maximizing profit, at the cost of my user experience... either you give me a cut of that, or I'm going to leave and take my content away with me. I don't want you maliciously profiting off of my content which I spent my time creating.