There is no point on getting to mad about this situation. it's only bad for your health.
Ark was built on an older version of the Unreal Engine. Highly un-optimized, single core, bad memory management, etc....
WC will not port Ark to a better version, they just don't bother and would be too expensive.
It's amazing to see what a modern UE is capable of on other games that can process thousand of structures with no effort.