No one blames them for trying to balance costs vs income. People are upset about them being greedy. Yes, they pay for hosting of the content, but the content was not created or provided by them. The content is from the community.
They have shown recently that they don't care what the community wants. They want what they want, which is to be profitable so they can IPO. They are willing to lose all of the power users they have pissed off in search of that goal.
That is not a place a community can thrive without being inundated with bots spamming the living dog shit out of it. A community that is built and moderated by itself, cares about the content. Reddit does not. They now care about the money.