PC-E Why does Nikon let Canon crush it in this area?

Your premise is flawed. Nobody is crushing anybody in this arena. The new 24 Canon is good, the old one was junk, the 45 is still junk and the 90 is quite good.

Nikon's new 85 is quite good and the old 85 was quite good, the 45 is junk and the 24 is good.

The 17 Canon is interesting, but really, when are you going to use it?

If you want "Crushing" go to the wide angles where the 16-35L II is junk and the 14-24 Nikkor is arguably the bet wide angle zoom ever made.

Just my opinions, but they're all based on ownership and years of usage.