I'm not sure how you can say this for a company that's notorious for using closed allocation.
Worst horror story I've heard, here on HN, was an EE who was also good at Python. He sure thought he was hired to do hardware, but found himself stuck writing Python to test hardware. Not wanting to end his EE career, he of course had to resign.
And, yes, I know in theory you're able to quickly transfer out of that first position if it's not a good fit, but like the anecdote above, we've heard too many stories where that doesn't work in practice.
As others have noted, the whole thing for non-VIPs seems expressly tuned for new college graduates, who, in the case of this closed allocation policy, generally won't mind working on "whatever" for 18 months.
But, to more directly address your question with the information I do have, there are a lot of things that make a job good or not good. When it comes to a lot of the other things - benefits/perks, ease of getting things done, low overhead, responsive management, good culture, smart colleagues - Google does very well.
w.r.t. the actual job spec and happiness - all I can say is that there's likely to be a bias in hearing from people who were dissatisfied. But, again, my colleague set is biased towards seniority and people who've chosen to stay, so either way, you're getting an uneven view. :)
The note to which I responded was by someone who had never worked at Google, and was making a large assumption based upon their experience at an unrelated company ("a large health care company in the midwest"). Many of the things in that note are factually incorrect as a basis for comparison ("mediocre benefits, and mediocre pay", said no Google or Facebook engineer, ever).
The point raised by hga has more to go on -- I don't know how common it is to be stuck doing things like that -- which is why I gave a more careful response to it.
(As an aside, I don't think it adds much to the discussion to make a personal attack or a categorical attack against people based upon their education. I welcome criticism, but it's certainly not fair to judge all Ph.D.s based upon my response, as much as it's not fair to assume that everyone in Kansas City misuses apostrophes based upon yours. :)