The update was beneficial to the interest of Google users. Those users aren't forced to use Google.
And even though Google is huge and gets great boons because of its size, it is also on a knife edge that could come toppling down because of a technological break through, or advertising collapse. In all respects Facebook is big enough to force that to happen (at least on an advertising front), but it could always come from an unexpected area as well.
(granted that a technological breakthrough seems doubtful, but often thats where the biggest surprises emerge)
The problem here is Google is selling the ads and also determining the traffic to the ads. It's too much in one place and ripe for abuse and the abuse seems to be happening