So this has been a bit of a peeve of mine over several games. The game doesn't do a very good job at conveying comm rose information. You request ammo or health and nobody notices cause they don't really receive that information from the game. The only thing indicating that someone is requesting anything is in the text chat box which most people aren't going to see. It's something I've fallen prey to as well. People have been asking for health or ammo and have had to chase me down and shoot at me or stand right in front of me to get my attention.
What I feel would be better is to bring back HUD elements that alert a player only when someone is asking for assistance specifically through the comm rose. Something similar to what is already in place for downed players for medic. Something like these hastily edited shots: