While I do agree that cheaters should be banned in a game that has such competitive things as leaderboards, this is also in a perfect world.
There may be games that have successfully did away with all cheaters, I would have a suspicion that these said games have not reached the popularity of a game like diablo. Which results in more players and the more players, the more cheating will be used.
Cheating goes hand in hand with competitiveness as well…to think of how many competitive sports players in every sport throughout history has cheated to gain the upper hand…because they want to win.
As for D3 at its current place in time, I do not see them having a legit reason to go all out on making sure all cheaters have been dealt with every single season multiple times per season…I mean, aren’t they on limited funds and personnel now?