I don't think we all need to sign this one. I think most people are resourceful enough to find the routes that work for them. Relying on others generally leads to disappointment. More specifically:
1. Seattle has published bike maps of the city, and King County has bicycle maps of pretty much half of the eastern shore of Puget Sound. If you're using these maps to find the handiest MUP, they're very useful. If you're trying to get from point A to point B in the smallest unit of time, with the least amount of exposure to heavy traffic, not so much. The routes suggested on these maps aren't horrid, but, in almost every case, there are much better routes, often a block or so away, that are simply not on he map. I find that simply using a regular city map, or my memory, to find my own damn route is more useful at least 85% of the time. I don't see how Google would improve the situation all that much
2. Google isn't very good compared to common sense (though they appear to be much better than other mapping sites). If memory serves, when I drove a car they sometimes suggested routes that were either slower than the optimum, or simply impossible for geographical reasons (e.g., there was a ravine in the way).
If Google wants to offer bicycle route maps, I welcome the extra resource. However, I don't think it's needed, and I certainly won't put any effort into pressuring the good folks at Google to do my thinking for me.