I added some mods for this in Ins 2014, and Daimyo took it to the limit with the Sernix server, but I have never really liked the way that disabling players and/or medics changed the gameplay.
I personally felt like it eliminated the tension of "one shot and you're gone", so it helped foster gameplay that took unnecessary risks and degraded the tactical gameplay.
As far as realism, I put that aside for video games when the game mechanics would suffer, and I don't like any mechanic that takes away player control in a way that locks them into a position or degrades their mobility, without being balanced out.
Without a healing mechanic, that would make mercy killing teammates for a respawn wave the only way to heal them, so I'm not a fan of adding this in.
That said, it should be a mod option so that servers that want it can do so, the popularity of the Ins 2014 medic plugin shows that a lot of players do want that mechanic in play.