The hiring process is this way for the entire industry. Multiple startups have failed trying to move it away from its current incarnation of technical phone screen -> technical on-site, where the majority of technical questions asked are data structures, algorithms, and system design based.
Implying that the people at Google are only good at whiteboard interviews, and not much else, in terms of both intelligence and technical ability is laughable. Google's influence on software engineering is broad and deep. Their papers moved the industry, their open source projects power the industry, their internal tools influence shifts in the industry.
There's something wrong with you when you let their signal / data gathering for their hiring process impair your ability to see what they contribute clearly, and what obviously works for them in terms of hiring able engineers.
Using this issue, which is clearly not related to engineering ability (it's a systemic management issue as far as I can tell), as a data point to demonstrate that their interview process is flawed, and that the engineers that made it through it aren't able says more about your own emotional state.