It makes the most sense if you think about it from the sim's perspective rather than your own.
If they want to keep their stuff they will be taking it with them.
If they want to sell their stuff they will be getting money and leaving the stuff behind for someone else to use.
But honestly, I find it confusing too and have occasionally done the wrong one because the wording tripped me up. So I always use "evict" when I want the house left with all the stuff still in it. I can testify that when you use evict, the sims getting "evicted" do get the money, not just for the stuff, but for the whole lot as far as I can tell. I move sims in and out of residential lots for screen-shooting purposes all the time in two SimLit stories I am writing, and I always use evict so that I don't accidentally mess up my sets.
