When you operate on the scale of Google or Facebook, getting "cute" will inevitably end up with some angry users. But without little touches like this, the company would move closer and closer to the IBM-esque corporate monolith. And neither the users nor Google want to see that image. That said, maybe this one was pushing it. I saw that this morning and thought, "Oh, here we go..."
Personalizations are cute so long as you have a personal relationship with who is doing it. If Google was a three man team who interacted with their userbase on a regular basis then these acts of personalization would mean more. But a 26,000 plus employee company having faceless developer #014345 implement feature #21542154, is much harder to pull off as being personal or cute. Especially considering how impersonal Google is towards customer service. It can come off like a socially awkward geek trying to make conversation...
Here let's remind you about your great father(or possibly your dead, abusive or absent father) to show how human & personal we are as a company, but if you actually have a problem with one of our products or services good luck actually getting a personal touch then.