What exactly is the problem with the current system?

That players should ALWAYS get a yellow card/red card if they injure another player?

I take it you don't watch real life football. Not every decision is going to go your way...

Also, considering that most of the injuries sustained are 3 days or more, that would mean a lot of suspensions for many matches. Punishments are given for the severity of the tackle, not the severity of the injury... Why should a player get banned for 3+ matches when the injury times are pretty much random?

Sorry, I don't like this suggestion. It's fine the way it is.