To preface this, I personally feel like the 'rigging in private servers' thing doesn't make a lot of sense (Though I can see potential scenarios where it could be an issue [See: User A runs successful betting server, DP gets large, User A calls friend User B up and arranges to rig a decap in order to claim the prize, people get mad, bla bla etcetera]). That said, the fact is that the rules are what they are and my doubts about them don't mean I won't enforce them. Because, you know, that's how rules work.
That doesn't mean the rules can't be changed, though. I suspect one of the reasons behind the rule being as broad as it is was simplicity - it's a lot easier and less conducive to loopholes or weird edge cases when we simply have a rule apply across the board, and this was one of the situations where there initially didn't seem to be too much issue with applying it across the board (Since peoples' TC was in play, and generally that'll tend to transcend any 'private room' stuff).
However, I think the right combination of ingame commands and adjusted policy should pretty well cover any of those edge cases/loopholes. The only real objection I can see to the proposed commands is again a simplicity one - it's generally preferred to have fewer commands, so that someone wanting to hop online and play doesn't have to spend an additional 10 minutes making sure that every single setting is correct. However, if we default to the setting that protects the room owner best (i.e. decap prize off, do whatever the fuck you want) I don't think that objection is too much of an issue.
If we can figure out an ideal set of commands (Right now I like being able to turn it on and off, see contributors, and clearing it - not certain if the op/all distinction proposed by pouffywall is entirely necessary) I'll add it to my list of requested features for the game devs. In terms of the rule itself, it'll either have to stay as it is until the commands are added (See #1 below) or we can talk about changing it so that it works with the current state of things. Obviously, no matter what we end up doing with it, using decap prize as a means to illicitly transfer/'launder' TC is still very much against the rules, but I don't think anyone will disagree with that.
Please note two things:
1. I cannot promise a timeline for when the commands will get added, if at all. I'll put it near the top of the list in terms of priority, but dev is fickle.
2. People who are currently banned for breaking this rule aren't going to be unbanned just because the rule is under discussion (or if they're still banned if/when the rule is changed). Depending on the circumstances we may be willing to reduce their bans, but the fact remains that users are expected to abide by the rules in place. If people disagree with a rule they should bring it up for discussion (As was done here), not break it and then insist that it's unfair.