If a bad player plays Malzahar, they are one of the easiest champions in the game to beat.
Despite popular belief, winning as Malzahar is not easy if the opponent knows what they are doing.
"Just press R" literally does nothing. Like... less than his E does.
So if you are dying to just R, you are already very weak to begin with.
Landing the E plus R takes time and allows for you to do things to prevent it. Also, you still have to already be weak.
Only if he is extremely fed can he one shot anyone.
On the other hand, someone who understands how to use him, will do more damage with E + Q than R will do for quite a while in game.
Generally, the role of Malzahar, as pointed out above, is to stop the champions that ruin the game for everyone else.