Being a long reliever isn't glamorous, though it's not like he doesn't get to fly on the team charter.
For the most part, the long man is going to pitch when the game is out of reach, either way but usually when his team is getting trounced.
There are exceptions, like injuries or extra-inning games, and the long man can help pitch his team back into a game if the offense cooperates.
It goes without saying that the hope for a team is that it rarely had to use its long man.