Static vs Mobile Defenses

Clearly the game needs some sort of money map. Something where you can build extractors anywhere and not worry about extractor points. Some kind of... metal... something something.

Hehehe

But seriously turtling is fun and one of the reasons why i always chose TA over Starcraft. I think this is the best post in this thread:

More land controlled should equal more economic power. If you turtle in a small area don't expect to win against any good players. Turtling sacrifices a larger economy and mobility for a heavily defended position that will not be easy to take over.

Hate to say it, but it looks like you missed the entire command and conquer series, along with the company of heroes series... They both employ those techniques (CoH employs a lot of cover-based bonuses and negatives as well as sandbags/barbed wire, and the older C&C games allowed you to build barricades from the aforementioned materials to slow down attacks and create (very temporary) pinch points)