I assume that the Epic supporters rather are hoping to get Apple to reduce the 30% on all transactions (or on all transactions of some type), not just to get Epic to be a special case. I'm not sure they have a case, but I think you're misrepresenting them.
Well, of course; if someone is supporting a company's position because of that company's "character", that would be absurd indeed. Both sides are doing it for profit. That doesn't mean we can't support one or the other on other grounds.