We wish that passengers knew that there aren’t spare planes and crews just sitting around at every airport. The plane you’re getting on most likely just landed, and depending on the length of the flights, this might’ve been your crews’ third or fourth flight of the day. And when you land at your destination, their day is nowhere near over. If the plane and crew overnighted at an out station, the (only) crew will be coming from a hotel, with no backups anywhere to use if someone got sick. The plane most likely sat empty all night, or was maybe towed out of the way and then towed back. No maintenance was performed unless a write-up made it necessary.
What this means is that if there’s a delay or mechanical problem, it’s real, and the crew are no happier about it than you are.
They know they’re going to be running late all day, with no time to duck in and grab a sandwich at the next stop. I’ve heard it all: “They’re LYING to us! I know they have one thousand crews based at XXX – just get another one!” There are no “justs:” just get another plane; just get another pilot or flight attendant. They “just” aren’t there, and any airline that attempted to staff and equip at that level would be so outrageously expensive that you couldn’t afford to fly on them anyway. We can’t always “just” fly around the weather, even if your brother-in-law says the weather’s just fine at his house. Sometimes you’re stuck a hundred yards away from your gate, if only the ground crew would “just” come out and park you. But they can’t:
Would you want to be standing in ankle-deep water out there?
So I guess the takeaway is that if you can think of a simple solution, we’ve thought of it too, and if we’re not already doing it that’s because it wouldn’t work. We really are trying everything within our power to get you there on time. Because it makes our days go smoother, too.
Source: Quora