Sure the primary concern for Apple is users. But it's not like the platform could exist without the ecosystem around it, which largely depends on developers publishing apps. And it's not as if the dev accounts are not subscription-based - it's not expensive and Apple does not make a ton of money on this, but it's not free either.
And I don't think anyone suggests Apple should get rid of all the rules and accept anarchy on the platform, that'd be insane. They have the right to set the rules on their platform, and enforce them. And the developers should not be surprised when violations are handled accordingly.
The first problem is that a lot of the rules are entirely vague, to the extent that it's hard to make judgments based on the wording. (Essentially what we used to call "rubber law" years ago, a vaguely worded law that can be used to support whatever the state currently wants.).
The second problem is that you generally don't get clear explanation what rules you broke. That may seem reasonable, but whoever makes those decisions is bound to make some errors. And if you don't know what rule(s) you supposedly broke and how, you can hardly appeal the decision.
Yes, for Apple it's much easier/cheaper to provide as little information as possible, eliminating the issue of appeals (i.e. costs). But it's a bit of a dick move, really.
If you set rules for your platform, you really need to plan for proper enforcement, including providing information what rule was broken/how and allowing appeals.