And it's worth noting much of this is fairly standard boilerplate at most shops nowadays.

Personally, I use it as a gauge of trustworthiness of employers; I am more than understanding that if I come up with a great idea related to something I'm working on, it's probably a result of the experience I've had AT that employer and it makes sense that they have some claim to that.

However, when employers say that ANY idea I have is theirs, that's usually a bad sign.