One of the best aspects of PC gaming is it being an open market.
While I'm happy EPIC is supporting indie games, it's very clear they still don't understand the PC market at all. And I don't think many longer term PC gamers have forgotten EPIC was one of the first developers to hop ship off PC gaming and call all of them a bunch of pirates back in the early 2000s. So to come back still actively not understanding the PC gamer playerbase I think is not sitting well with people, and money hatting games to try to get people to come to your store (including games that were to be released elsewhere before this) and make people use more launchers, I think it's a bit obvious why people are upset over this.
Since Steam has to come into the picture here for discussion inevitably, Valve has never money-hatted any of their games, and have even allowed their first-party games to be sold on other stores. They attracted people through their specific launcher's features and single-handily revitalized PC gaming and set a standard. If other stores can't meet that standard and try to force their way into the market by money hatting games and not much else, it won't succeed. Money hatting is something many PC gamers hate and what made PC exclusive gamers often leave consoles in the first place since the dumb "money hatting" of games locking them to a single platform is tiring stuff to deal with, it isn't an attractive appeal to PC gamers and one they'd be understandably upset by seeing more corporations trying to approach PC gaming in this method.
Competition isn't bad, but the competition is not understand the platform they are trying to sell on and doing things that will actively turn-off their userbase. One of the big reasons PC gamers chose PC is because they like the openess of it, where to play your games, customize them, etc. So trying to close off games exclusively to certain markets is not the way to win over this playerbase, especially when there's already a standard in place here theseo ther stores aren't living up to.