Nah someone just forgot to run the code through a compiler. I hope they didn't lose their job, they're only human after all, we all screw up.
But yes the new patch gives amazing performance improvements compared to 1.3 and previous patch benchmarks.
Forgot to run the code through an
optimizing compiler. If they had forgotten to run it through a compiler, we wouldn't be able to play the game at all.

Good improvements. However people still running massive mods with ENB series and high end shadows only seen minor improvements. Yes there are performance gains but not as much as I was expecting. People were yelling omfg I was at 30 fps in whiterun now I am at 60 with the beta. There was no such huge improvement gap for me.
Compiler optimizations only help when you're CPU limited.