Whether the MS rules are fair or not is debatable and a matter of philosophy.
If you believe the rules should only penalise players that show intent, Twizz is absolutely right.
If you believe that shooting your gun and possibly eliminating opponents after being hit, should be penalised, irrespecitive of intent, then the rules are fair.
Personally, if I get eliminated by a guy who is already hit, I would greatly appreciate he receives a penalty, to balance that out.... and as the refs have no way to ascertain consistently when this occurs and routinely eliminate players getting hit by someone playing on, I like the rules to be on the side of the "victim" rather than the offender.
But, as said, it's all about philosophy, and as such difficult to reach a conclusion on.
Now, do some MS refs go completely overboard and eliminate players when they shouldn't, according to the rules? - ABSOLUTELY.... but that is not a rules issue, that is about them not being trained well enough, or having the wrong kind of personality for reffing.