For me it's a matter of space, time and money. I don't have the space for another rig (wife is already pissed enough w/ two large dynamic rigs), I don't have the time to build a stat amp any time soon (and whenever possible like to build my own gear) and just don't want to dedicate the money to stats right now. Hell, neither of my dynamic rigs is really even close to done so throwing another completely different beast into the mix is a bad, bad idea. Plus, I'm really pretty psyched about where my dynamic rig is headed and want to see that through to at least some measure of completion.
I've been presented with several tempting offers lately and managed to shut them all down before I got going. It hasn't been easy, but I'm sticking to my plan so far.