Welcome to Flyertalk,
Katy_L!
I have to agree partly, not so much with the room availabe issue since I'm usually one of the first on/off, but more so with the dimbulbs that are allowed to carry-on oversize pieces then delay departure while scrambling for space, on-flight luggage checks, etc. Usually the same idiots who can't find their seats because of the non-intuitive nature of numbering rows and alphabetizing seat locations.
As much as I hate to say this, I lay the problem directly at the feet of the airlines who continue to allow blatant disregard for the size limitations on c/o bags & number of c/o pieces allowed by pax.
<end of rant>