For me, the only reason I will never go back to GOOG is blind allocation. IMO that's a bug, not a feature.
Google et al often do general hiring. This means that they hire you and then later decide where to assign you afterwards.
I had thought at Google hiring managers could bid on you and some kind of choice could be made. But maybe that's only in big enough offices with good enough resumes.
It's bad because you don't know which team you're joining and the quality of the manager. It's good because it lets the company assign you to the most important areas first.
Contrast this with a normal process where the hiring manager for the team you're joining is in the interview loop. You know ahead of time which team you're joining.
That hugely slants the purpose of the interview toward Google, as the candidate really has no idea who they will be working with, or how they think. The interview should go both ways and provide information to both sides on if it's a good fit, but at Google, they go only one way.
This might be a small point for most, but for minority candidates, knowing who you will be working with and having confidence they won't actively cause you grief is a big sticking point. At least it was for me (I turned them down).
That's why I mentioned that I've been asked to do lunch or a phone call with prospective hires. I'm not a manager, just a grunt, and these candidates wanted to speak with people from the team.