[Kalimac]

It's true that Gandalf had powers infinitely greater than those of anyone else there, and was the only one remotely qualified to deal with the Balrog, but I never got the impression, from that line, that he was thinking about himself much. It was more, as people have said previously, "Get out of here before you get killed!" And I don't think "fools" was meant arrogantly, more it shows just how desperate the situation was, and that Gandalf, Wizard though he was (as JRRT) would say, was afraid. If you're very angry or very upset you tend to say things like that; it doesn't take much. Who hasn't sat inside their car on a frozen morning, trying to get the thing to start and muttering "Come on you worthless piece of rust, start!" It's the same principle, only of course about five hundred thousand times more serious.