I so agree. Most competitions are spent running from warmup to competition floor back to warmup. When we actually do get a moment to sit, it's nice to be out of the arena with the blaring music (by this time, massive headaches begin). The coaches room is a nice spot, away from the craziness. A lot of contacts are made that end up being beneficial to programs. Plus, it's nice to read and go over scoresheets without everyone breathing down your neck.
ETA: if the coaches aren't there to socialize, than neither are the kids. Half the fun of competitions are meeting up with friends you haven't seen in awhile. This is no different, whether you are an adult or child. Competitions are the place where all the hard work comes together and you get to enjoy yourself. If I wasn't allowed to enjoy a competition, why would I want to go?