1. Epic's poor business ethics, such as bribing developers with lower fees to make their games exclusive on Epic's store, even when the game was already available for early access play and pre-orders on Steam and elsewhere. This sucks for the people that expected to play it on Steam and then weren't able to. Examples include Phoenix Point and Metro Exodus. And Epic is still doing this, too. They're going after games that are slated to launch on Steam and GOG and they're offering them funding to pull those releases and to go with Epic for at least one year. That's really poor form.
2. Epic's game client sucks. It's lacking in features compared to the others and it's terrible at resource utilization.
3. Epic is collecting your data. Not just which game you're playing and your hardware configuration, but also things like what media you're streaming. Do you really want yet another company collecting information about you? Isn't Steam bad enough without adding another one?
4. Epic is 40% owned by Tencent, a Chinese company with ties to the Chinese government. Maybe you trust the Chinese government not to misuse any of the data collected by the Epic Store. I sure don't.
Look, I think we all understand why Soren went with Epic. They gave him funding to finish the game and otherwise he might not have been able to finish it at all. But, please understand that some of us aren't going to sign up and install Epic's client just to play this game. I think it's OK for us to express our disappointment in the situation. Epic doesn't need you all to defend them. They're big boys and girls. They can handle some criticism.
If we're all lucky, then Old World will only be exclusive for a year and then we can all play it elsewhere. Ideally, GOG. And hopefully, Soren will have the foresight to make his own mod manager and whatnot so that mods aren't tied to a single platform. It really sucks when you buy a game on GOG and the mods only work in the Steam Workshop, or whatever. We all pay the same price. Let's all get the same features.