Standing for ages at IAH to board UA1178 to SFO, the lines became long and unruly. For anyone who newly approached the gate, it was almost impossible to determine which line was Group 1 (which ended up with about 80 people in it). Then two people stopped with their baggage over to the right of Group 1 and then a 3rd person thinking that THAT was the line stopped behind them. Soon a rogue line was forming of people who honestly thought that they were in the right place. I went up and mentioned the problem to the person in charge of GS pax, and "Sorry, that's not my job" was the response. "Sorry, that's not my job." is a phrase that no UA (or any employee) should ever utter. How about, "Oh, sorry about that. I'll find someone to take care of that." instead?