I really feel if an exploit effects the leaderboards in the slightest, it should be bannable, I mean, for some classes the full set of passives was next to useless, but for others it was fairly godly. If it's an exploit that gives you an in-game advantage it should be an insta-ban. For those who literally just put the passives on in town to see it work, I don't see the harm in the curiosity, or maybe going into a duel to test them out etc..
Bots are another story, they're super hard to detect now a days as they're becoming more and more prominent at what they do. It a perfect would they would be banned as cheesing paragon levels is pretty cancerous for ladders.