Because it's a non-issue that affects an insanely small portion of people, but people love to shit on Pixel.
There's also no proof as to why it happens. People speculate it's the cold weather + warm pocket that causes the metal to shrink/expand causing the cracking, but there's zero proof. For all we know these people drop their phone 50 times per day, weakened the glass, and "oh no, it just exploded out of no where!!!