I wouldn't say they never do that, but it wasn't my experience there recently - you're supposed to only be able to get to the guest floors by using your key in the elevator anyway (though you can actually just wait till someone swipes theirs, and press a button before they do)

If you're going to Marquee, then a single room key only lets you skip the line with one guest.

The couches in the terrace suites are comfy, though I'd rather my own bed and space too (besides, you're in Vegas... if you have guest(s) over, who wants to be sharing a room? )