This is a pretty big call. Its one thing when a council requests such replacement. But doing it without such a request is undemocratic. It was undemocratic in Canterbury, and it is undemocratic here. If elected councillors spend all their time on petty disputes and behave like children, that ultimately is a problem for their voters to sort out, not central government. And voters are perfectly capable of it: look at what happened in Horowhenua when it had a similar problem last term. If the Minister thinks there is an absolutely irreconcilable problem, then she should exercise her powers under s258M of the Local Government Act, call an election, and let voters decide. She should not impose unelected dictators with an agenda no-one voted for. Again, see Canterbury for the manifest wrongs of that path.
(But voters could just vote for the same people again! Yes, they could. That's their choice, and if they do, it's its own punishment, just as it is for central government. Because like central government, local government is meant to be representative and democratic. Its not there just to be a manager for Wellington, and if Labour thinks it is, they deserve a kicking at the ballot box for it).
While I'm on this subject, this is altogether too easy. When National did it, it required a special Act of Parliament to overturn elections and oust elected councillors. But those powers were then inserted into the Local Government Act, and so now Nanaia Mahuta can do it just by writing a few letters. Given the gravity of the decision to suspend somewhere's local democracy, that seems far too trivial a process. Democracy deserves better than this, even shitty local democracy with its second-rate egos. These powers should be removed from the Local Government Act permanently.