It is not the job of the ramp agents to explain why a flight is delayed. They have no control or input to the decisions made. It's like yelling at a waitress for the restaurant being short-staffed.
I fully agree, however there is sometimes more to the story than meets the eye. Years ago, I was flying in the jump seat of a United Airlines A320 as part of my job (I didn’t work for United, though - I worked for the airport). A friend and colleague of mine was the captain of the flight. As we were sitting in the cockpit preparing for the flight, he was informed that an inbound flight with a large number of passengers connecting with ours was delayed leaving their departure airport.
The decision was made to delay our departure to wait for them, even though that would mean delaying our flight well over an hour (I think it was nearly an hour and a half if I remember correctly). So, at that point everyone from the flight crew to the gate agents knew that we would be delayed and exactly how long we would be delayed. However, the captain told the gate agents to roll out the delay news to the waiting passengers in 15-minute increments. They first announced a 15 minute delay, and then kept announcing extensions of that delay about every 15 minutes. Also, it was a long time ago, so I don’t remember for sure, but I think I remember them giving the reason for the delay as “air traffic control delays.” That’s a commonly-used excuse, by the way, and was in this case a stretching of the truth if not an outright lie. I don’t remember why the connecting flight we were waiting for was delayed, but our flight certainly wasn’t delayed because of that. Also, “air traffic delays” is a meaningless term, and when given as an excuse is almost always false, unless there is a ground stop for some reason. There are delays that frequently occur due to congestion and inefficiencies at certain airports, but they aren’t the fault of ATC, and those delays are already built-in to airline schedules. Often, they’re caused by the airlines themselves when they schedule a bank of flights that is too large for the airport to efficiently handle all at once.
It was a pretty eye-opening experience, and I’ve noticed a few times since then, when I was just a run of the mill passenger, delayed flights where the airline seemed to do something similar (though not being behind the scenes in those cases, I had no way to know for sure). I do know that my experience was not an isolated incident; airlines do sometimes roll out bad news in small chunks, rather than just leveling with the passengers from the start, and when that happens all of the airline employees involved know about it, even though some of them have no control over the situation.
there is difference between having no control of the situation and having no information. The airlines would have better public relations if they informed the passenger of what the problem was.