Earlier quoted context omitted.
This is a bit like saying "I don't get why web development is overworking people, just look at all this cool stuff Google is doing with the Go runtime!". Most people who work in the game industry are not doing deep game engine hacking, but doing grunt work like scripting/designing some scene in a giant adventure game who's going to have thousands of those, and all of those need to be finished before the release date.
I wonder what the turn-over is for engine programmers? I'd guess very low. I wonder how many commercial engine programmers there actually are, anyway? I'd guess very few.
There are only a handful of major engines today and it's been that way for years. Unreal, Unity, Frostbite .... a few games still roll their own but the costs of keeping up are getting extreme.
I really doubt the Unreal Engine developers feel abused. For one thing, the release schedules of engines and games are now to some extent disconnected. Games get whatever the engine can do. Epic isn't going to move mountains to add a feature to UE for a licensee unless they get a TON of money to do it.