Space heaters have their role .... and they are frequently abused .... but let's look at another part of the questioon: component ratings.
Let me begin with a colorful example, using footwear. Shoes are shoes, and all are rated for 'walking.' Yet, I wouldn't wear my metatarsal / steel toe boots for dancing, or hike the Applacian trail in heels.
Sounds silly, doesn't it? Yet, we assume all receptacles are equivalent just because they're UL listed. Ditto with switches. Wel, UL has some pretty thorough testing, but you can be sure they don't cycle them on and off of full load for nine months. There are many, many items that wimply won't last very long when pushed to the limit. I mean, ever look inside a power strip, and see just how flimsy those are?
Switches require special attention. Did you realize that the 'usual' light switch has only a 10 amp rating? Look at the markings on the strap.
Receptacles run from 50 cents to 15 dollars .... one would be foolish to assume that all were equally stout.
