Two reasons. 1) you need lots of flights to warrant the costs of opening another domicile, and right now there just aren't enough.
2) our contract states that we will have all the different reserve windows. 4am, 8am, noon, 5pm, etc. I don't know if there has to be trips built to certain specifications or not, but if 60 or 70% of all the flights are red eyes, you can't really make it a pilot domicile.

This of course could be fixed by the airline growing LAS and offering more of a variety of flights. Which is fairly likely, considering we've got 100 airplanes in order. You have to fly them somewhere. I also heard BB state in ground school last year that Vegas could always be a flight attendant only base, like TTN.