Having healthy competition is a good thing and I’ve wished for a competitor to Steam for a long time until one day the monkey’s paw curled and we got Epic Game Store. To sum it up:

• Epic actively tries to introduce exclusivity deals to PC, something that goes very much against the nature of the platform. It is something we’re supposed to be above on PC and let console players deal with. PC gamers simply don’t want fragmentation in the market. We hate all the different shitty launchers publishers are making for the same reason too.
• Epic has a very hostile attitude towards Linux. Their anti cheat for example by default detects the mere fact of using Linux as a hack. For a long time if their anti cheat was included it was an absolute no go on Linux. Their store also works like crap on Linux, if at all.
• EGS lacks necessities for then to call themselves a good store like reviews, good support and refund policies, ease of mod support, wishlists, etc.
• Their UI is just plain bad.

But the main point is the first one. If they bothered making a good store they wouldn’t need to make most of PC gamers angry by introducing exclusivity deals, but they can’t be bothered to do that, so they go for hostile competition instead at the detriment of the customers.