Operations knew but they didn't tell the passengers!

I'm sitting here in Denver waiting for flight 5347 to SAT (originally scheduled for 3:35). No one came to the gate to announce that the flight was delayed. At 2:30 no one was at the gate. I had to do everything imaginable to understand that equipment issues caused the delay. Well guess what, I was told that operations knew there was an issue, but decided to not tell anyone, not even the gate supervisor. So if I would have known that there was an issue at 2:30, I would have changed flights. The "holy cow I have a problem" station had 4 people at the 4 station counter just 50 feet from gate 85, yet no one could make an announcement about the status of the flight. Now because I did not know there was an issue with the flight, I am here for another 3 hours waiting for what I hope will be a flight to SAT. If operations knew that they did not need to send a gate agent to gate 85 at 2:30, why didn't they let the passengers know. I flight a ton of miles on United and this is really poor form....unbelievable!