I think what you listed is the reason why.
I have seat covers in my Jeep, and put in $50 heated seat pads from Amazon in between the seats and the covers. They came with the switches, wiring, etc. They heat up quite quickly and have worked great for 5 years now. Best $50 ever spent. Yeah, the switches don't look factory, but they work great.
These are what I bought:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1