Because it serves no real purpose. You throw the quick release and now have to unscrew the nut to free the wheel. And then unscrew some more till the "quick" release does release.

You have to do this for flat tires, too.

But then you have to fiddle with the nut and refiddle to get the tension right for the quick release to hold properly. On the ground it's half bad, on a rack it is more bad.

So what purpose do those ridges/clips/lips serve? None. If I put the wheel back on and absentmindedly forget to tighten the nut, it is just the same as if I had placed a fork with none of that onto a wheel and forgot to flick the quick release.

Oh, I guess, if the quick release accidently opened....Not in all the years...

Oh, well, I may wait out the warranty period before removing the label from my bedding.....