I think what they are angry about is that Google claims to be the first one to do that (when their startup has been doing this for long) and since Google is so well knows the world is thinking they made a local (India specific) innovation.
That's a great point. Why didn't RouteGuru raised a voice against Yahoo? Let me explain:
1. Yahoo din't talk to RouteGuru team before the launch.
2. Yahoo also din't come up with any false story either and there team did mention about RouteGuru in one of their Blogs.
I urge you guys to understand the point of disappointment well.