Well winter is nice compared to the summers we have here. Frostbite might suck but trying to stay cool in 100+ temps has proven to be quite challenging. The way I see it, I can layer up to get warm which also adds more protection. But when it's hot, getting cool is impossible and a lot of protective armor gets sacrificed. Even textile jackets can be suffocating in the dead of summer.
Think of the pounds you can lose sweating your arse off in leathers without going to the gym and half killing yourself. Rather be hot and sweaty than cold and sleepy. A good undersuit helps keep cooler, too may layers when trying to keep warm deadens the senses.