As a fellow Floridian I can understand your confusion .... we do not have to worry very much about freezing. A simple shed or even a garbage can can keep our pump equipment from freezing on those few days when we MIGHT get cold enough for that to be a problem.
In other areas where they not only have freezing worries, they also have basements and/or garages where they put things like this to keep them out of the weather.
Additionally, unlike Florida, where the well casing is terminated above the ground level, they terminate the casing below ground level (below the freeze line) to protect it from the cold - thus a "pit" is needed to access the well head - and they run all the pipes that deep or deeper. Because that pit is a bit of a pain to work in, an enterprising man (about 1941) developed the "pitless adapter" so the the drop pipe (and pump if submersible) can be pulled without actually having to try to work in the pit.
By using this method, well and/or plumbing work can even be done on very cold, freezing days. They can even replace the tank, switch and/or controller in relative comfort instead of having to dig mounds of snow from the well area and getting all wet in below zero weather.
Don't get me wrong, I know there are some additional cold days up there in Seminole Country that we here in Gator Country don't have to deal with, but Leon County never has the type of cold they have in Colorado, Canada, New York and almost any place a bit north of Thomasville.