Section 17 of this ridiculously extensive Reddit post that I found summarizes the reasons that people might be upset with Double. I cannot verify the accuracy of the information myself, but, if it’s true, preventing Double from entering further contests seems more than reasonable:
https://www.reddit.com/r/HobbyDrama/comments/kks2pd/lego_building_bionicle_canonisation_contests_or/
The phrasing here is important. While it is true that Double’s victories caused events that led to his ban from future contests, you seem to be implying that TTV is banning him simply because they don’t like his entries.
If Double didn’t win the Helryx Contest, he wouldn’t have done what he is said to have done in the Reddit post above; if he didn’t win the Bomonga Contest, no one would have cared about the shield position or the height comparison.
In both cases, Double’s behaviour likely would have gone relatively unnoticed if not for his victories, but that does not excuse the behaviour.
I’ve had this feeling for a while, but I’ve never been able to articulate it; you’ve put it perfectly here, though. A ban from a particular community hub should not equate to a ban from a community-wide event.
That being said, in relation to the above discussion, I still think it’s reasonable to ban someone from the contests for infractions of contest-specific rules, just not TTV-specific rules.