It's bad for the company. It's bad for the industry. And it's a much more straightforward advancement model for the individual if they know how to exploit it. That's a very particular kind of "unhappy".
Getting promoted at Google requires serious gaming of the system, especially once you go for L5. Very few people in the system at L5 or below think it is easy to exploit, even if it is supposedly "straightforward".
Decision making is opaque, even if the process is technically well-documented. One committee isn't bound by what the previous committee decided and on and on.
And yes, I think quite a few of the rank and file are unhappy about it.
