My own experience is that I got into the market while others were perhaps getting degrees, and after 25 years, I am going back to school to get some math and theoretical background that I find interesting.

When I didn't have a degree of any sort, I was very dismissive of computer science degrees. I imagine that cain's experience and mindset works well for him, but I suggest that those contemplating a degree will not really be four years behind the market when they graduate. A good rigorous program can provide skills and theoretical grounding that one may or may not get with years of experience. So, that 4 year head-start that I got was nice at the time, but after 25 years, it doesn't seem like such a big deal.

I am not asserting that a good theoretical grounding is a pre-requisite for success, but I suggest that it can be helpful, and it is hard to imagine how it would hurt. It is certainly something that I am interested in.