There sure seems to be more "issue with tire pressure sensor" threads than there were ever "tire went flat and I never knew" threads.
Sooooo, why do we need sensors on a Viper? Particularly a Viper that comes with run-flats?
Well, because run-flats are a misdescriptive term, run-flats just mean they can go a bit further down the road before suffering irreparable damage from being driven on while flat. I had never had tire sensors before the SRT, and from time to time, my RT/10 tires would get nails and run out of air, though luckily I never had a significant problem. However, I don't check my tires every time I go out to drive my car, and I'm sure most everyone else does not either. Therefore, if you drive one day, get a nail and come home, the air runs out overnight, and you go out the next day, you likely won't notice soon and may have a problem.
A while back in the SRT, I left the garage and the tire sensor went off. I stopped the car, looked around, and the tires looked fine. I figured it was more likely that there was a problem with a tire than the sensor, so I took the car back to the garage and checked the pressure and found a tire low. So conceivably the tire sensor saved me because the rigid run-flats do not appear to be flat when they are, and I would not have noticed other than my occasional tire pressure check.