The explanation put forward in the recent Bloomberg article seems to do a good job of explaining the situation, though — Google simply put too much money on the table, and utilized a compensation system that was (seemingly) not well thought out.

Here are some of the most interesting parts of the article:

“Early staffers had an unusual compensation system that awarded supersized payouts based on the project’s value. By late 2015, the numbers were so big that several veteran members didn’t need the job security anymore, making them more open to other opportunities, according to people familiar with the situation. Two people called it ‘F-you money.’ …