OK. But employee surveys consistently show that people working at these companies are highly satisfied. That doesn't mean you'd be satisfied there, but I don't see how you can say that they are not good companies to work for.
You have to consider what those surveys measure, i.e. people who WORK there, not people who HAVE worked there. Thing to remember about top-tier tech companies is that anyone who CAN get a job with them can also pretty easily get a job somewhere else. This means that people who are unsatisfied don't stay very long.
You imply that innovation is the only thing an employee would want to participate in. I wouldn't have a problem working on a great team making great high quality products that are not innovative.
Consider this they collectively employ ~ 100,000 people and have produced basically zero innovation in the last 3 years.
PS: Though they also have fairly wide side doors so many of their current employes have not gone thorough their screening process.