I'm curious where you grew up. Heating indoor spaces in the winter has been effectively mandatory during the lifetimes of anyone who would be commenting here. On the flip side, air conditioning only became widespread during the lifetimes of many HN commenters, and the population explosion in the sun belt (desert southwest of the US) is a relatively recent phenomenon. So from a familiarity perspective alone, heat is far more popular. That's before you get into the way A/C is often treated as a luxury, from installation to utilization costs.
The Midwest. In my experience, either people have central air, or in older houses they put window units in all over the house.
All the apartments I see have mini-splits or in-wall units. I put a floor standing dual-hose unit in my bedroom where my desktop PC and server also are.
In upstate NY we have some summers with just a few days where I'd want air conditioning, we have some when I'd want it for July-August. Usually space blankets on the windows in the day and fans to thoroughly equilibriate at night get us through.
