I think an aspect there is that Google nowadays has quite a backlog of stuff, which just needs maintenance. Established products which each have limited room for big innovation. And maintenance doesn't work well with goofing around. And finding the balance between having maintenance work done and doing new things is hard. (Just see their messenging solutions ...)
At the same time at their scale the measures of success are different. If a solution doesn't reach a huge audience it's quickly lost between the big products, while it might be profitable.
Back in the days an Orkut which served primarily Brazilian audience was okay, but compared to scale of Gmail, YouTube and Search (and the aimed reach of Google+) it was a distraction, not helping the core brand.
At the same time at their scale the measures of success are different. If a solution doesn't reach a huge audience it's quickly lost between the big products, while it might be profitable.
Back in the days an Orkut which served primarily Brazilian audience was okay, but compared to scale of Gmail, YouTube and Search (and the aimed reach of Google+) it was a distraction, not helping the core brand.