He means they have a problem with Linux users. What other reason would there be to buy up games and remove native Linux support the second its removed from the steam store? (Rocket League for example)
The Epic Games Store doesn't have a Linux client, so it's understandable from a business perspective to not develop a product no new customers will be able to buy.
It's a middle finger to existing customers though, especially with the outdated Linux version being downloaded by default. They should prioritize proton to enable online play on multiplayer game, but as established, they don't care about Steam Linux users
Yes, those launchers are great. But I don't think Epic will ever acknowledge third-party clients exist, so their existence makes no difference from their perspective.
Eh... "gaslighting 101" -- swears randomly (against the victim/target), throws in a (non-random) praise to "raise the fire even more", refuses to elaborate.