Maybe it's a bit strange comparsion, but if you play football with your hands instead of your food, it's not allowed either and you will first get the yellow card (3 days timeban) and then the red card (permban - well in football just for the game, maybe a few more and not for lifetime).
The same counts for every other game as well. If it's Basketball, Tennis, Badminton, and so on. If you don't follow the rules and get an advantage to others, you will get defined with disqualification, even if you are playing this game for years.
Actually the same happens here. Blizzard defines rules, which we accept by playing the game. If we are botting, we have an advantage against other players and will get defined with bans, even if it's sad about the time we've spent.
Luckily I never have been banned yet, but I'm also not a hardcore botter and if I bot I'm not doing that do make profit at all. It's maybe just because I'm to lazy to farm the mats by hand and want to watch youtube videos in parallel. And if I'm getting banned I think I still can talk with the guys and tell them that I'm sorry and so on - from that point on I won't obviously do it anymore
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BUT I have to say, that from my point of view it's a 100% crap decision to sue now botting companies! From my point of view it's up to Blizzard to fix their product in that way, that botting is not possible anymore!
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By the way... Your examples are forbidden for completely different reasons! Xerox can't tell you to use Xerox paper for profit reasons! Blizzard doesn't make any bigger profit by excluding the botters... It's the other way around... If I hear some people have 9 and more accounts and are botting with them, they are paying blizzard every month. Those people for sure wouldn't have those 9 accounts, if they were not botting