Underinflated tires were blamed for a rash of accidents involved Ford SUVs that rolled over. Since then, TPMS is mandatory in US.
I like the system, although it tends to make me obsessive about keeping all the tires properly inflated. I particularly like the ability to flip on the pressure display if I roll over some debris at high speed. This once gave me early warning to exit an Interstate before losing too much pressure in one tire.
My biggest beef is with mechanics who swapped the sensors about carelessly, with subsequent ensuing hilarity as I try to adjust tire pressures.