Because with our RPI and SOS you won't find a team to have ever been left out with similar numbers, it's really that simple.
You don't think a team with a 51 RPI has been left out?
Interesting you keep pointing out the RPI AND SOS. You realize that SOS is an integral part of the RPI, right? It's not like you look at them as separate from each other. It's not like you look at UT vs Arky and say "well, UT is 51 and Arky is 58 but UT also has a much better SOS". That's already factored into the RPI.