If I was strategizing for AQ and actually decided I wanted to win this war (as opposed to just scaring and killing a bunch of Americans), your concept is what I would embrace. It's like a slow-motion D-Day invasion force, only very few are getting killed on the beach. Most are making it to their forward deployments. If AQ is thinking "victory", then it will be hell for us on the day the go order is given. Not that we will lose or give up, but it will be a "real" war on American soil.
You've hit it on the head. From AQ's perspective, 9/11 was a failure. It did not ignite a holy war between Christians and Muslims, at least not yet. 'Christian' response was divided, measured and limited.
With this scenario in action, can you imagine what Americans will do? I doubt the response will be termed as 'measured' for very long. For some reason, this is what the al-Qaeda types want. And just because it's what they want doesn't mean we shouldn't give it to them.