There is a difference between acknowledging the fact that there isn't much that can be done against sockpuppets and to support it.
To acquiesce something doesn't mean you say you'll never do anything about it.

regardless...

Even if UP had said that sockpuppetry is okay and he would have welcomed all sockpuppets with a hug and a cup of coffee I'd still not call it dishonest to do something about it now. Those people get their money back! They are not being robbed or anything they're just not welcome anymore. People are allowed to change their opinions are they not ?

Imagine this scenario.

You found a club for all the cool kidz and you even let in a couple of dbags because you think that it won't do much harm. If you later notice that the dbags are actually ruining it for everyone else would it be dishonest to kick them out of the club ? I don't think so.