They may not be able to heal themselves
Sniper / Scoped Assault / GPMG / Rocket vs Tech with no way to heal up = dead tech, which means less revives for traditional medics. Also means everyone would open with nades, similar to the way Brink plays.
I don’t particularly agree with is that in a team based game a medic can play a game for 20 mins without once considering helping his team or require help from his team.
They are helping their team by preventing their team-mates from being killed, and controlling areas in which their team-mates can use. Their value comes in longevity which is different from say the hyper, which is about max dmg in a short time frame.
But lets look at from your viewpoint of class actions.
*Sniper on hill
*FieldOPs with scope on hill + unlimited ammo
*Titan/Desie on hill driven by an engie
*Engie in flyer
A player can spend 20 minutes doing all those things and beast in safety.
None of them are required to attend to other team-mates with class actions.