The reason you didn't make it is because you didn't beat anyone -- 0-6 vs. the top 50, and 1-9 vs. the top 100. In fact, you literally beat one team in the rpi top 125
No offense, but I actually think this is an example of the new system working pretty darn well. The old system basically just slotted PIT teams according to RPI. Apparently this system is smarter and was able to recognize the fact that you basically lost to every decent team you played, and fattened up your W-L strictly against patsies. That wouldn't be enough in real life, and personally, I think it's a good thing that it's no longer enough here.
(And truly no offense intended with these comments -- I know that you're a top-notch coach, and were playing with a roster and schedule not of your own making. I just think the computer got this one right ...)