I'll never, NEVER give someone lip for not getting into the chair. When I play(ed) marines, my attitude is this: I expect that we'll lose. I expect that we'll never even get a second node up. I fully expect that nobody will touch the chair in the first four minutes - or if somebody jumps in right away, that he will be content with turretting up MS and never even get a second node. Why? Because in half the games I played, that's what happened, and this way I wasn't that disappointed.
Furthermore, being comm is a stressful, unrewarding experience. You have three times as much to do as a normal rine, and you'll get snide remarks (if not outright flames) if you lose. Honestly, who wants that? You work your ass off, you try to pull off a victory, you lose because your team wants to sit right outside MS and shoot incoming skulks instead of capping nodes for you (or defending those nodes from rampaging Fades), and then you get smack talked at you for it. That's why I'll never, NEVER expect of anybody to even venture close to that chair. It's the chair of hot coals and needle cushions, the chair of nail-biting and soul-rending.
And I have all the more respect for those that dare sit in it anyway, let alone do it well. I haven't even mentioned the crappy interface yet.
And if I ever play NS again, I'll probably kick anyone who as much as scowls in the direction of the comm. Even if he actually deserves it. Because anything, ANYTHING that makes the comm's job harder in any way at all is a crime against your entire team.
Which also means that you shouldn't all run away at the start of the game. Because a comm needs his team. Don't leave him all alone.