If you meant to say that Google's top engineers _used to_ work on the search engine but nowadays they work on making people click on ads because that's were the money is, then I wholeheartedly agree with you
No, it's like saying the best athletes of our generation use their gifts to get people to buy stuff. That's how they make their money, but ultimately it's not what they spend their gifts doing. They work to be at the top of their sport and other people figure out how to make money on that.
Successful/rock star athletes spend 99.9% of their time honing their athletic skills and the rest on advertising deals. Google on the other hand spend 99.9% of its time on making people click on ads. Because that's their athletic skill? No. Because money.