They have 2 sleeping surfaces...
2 queen - one as a standard bed and another as a couch/convertible bed....
Grand Floridian does offer the 2 Queen Setup in the new building...
Vero Beach historically did.
I believe Old Key West does offer 2 "normal" beds as well.
As for why no Kings - I think it is because they felt the sleeping 4 vs. sleeping 2 or 3 strategy was a better way to go... I also think it helps move people who want a king into a 1 BR.