I do think people get caught up in hating Epic, but the difference is that if any of those developers felt like releasing on another platform, they could. The "exclusivity", such as it is, is just happenstance. Whereas Epic's exclusives are largely actual contracts.

99% of the games on that list are small-time indie games that only release on Steam because that's where the market share is, and they probably only have the dev capacity to support a single platform. Steam also has a lot of API support for devs. Those games exist on Epic too, but when people complain about Epic they aren't complaining about those games, they're complaining about bigger games that are artificial exclusives, timed or otherwise.

Steam offers the better customer experience, and Epic can't compete with it, so instead they just buy exclusivity rights to games. It's arguably anti-consumer, and definitely different from those games that just happen to only be available on one platform or another.