That's reasonable, but you're forgetting the part where the CEOs don't want to be the CEO anymore. They've got billions and want to spend it doing shit like wifi weather balloons or self driving cars. So they look for someone to replace them, and that replacement doesn't have the tenure in the position to say "stop the bullshit, I want good products, not half baked 'revenue generators'".
But they do have an army of MBAs in the CFOs office telling them quarterly ad revenue is down 3% year over year, which means the world is ending, so they need to pump those numbers while everyone cashes out their stock before the rest of the stock holders realize the plan is to leave them now holding the bag for the now worthless-page-of-ads-before-search-results company.