
Devil's advocate here.
But, are they? When is one taxable by a jurisdiction? When does a jurisdiction reserve the right to assess residency-related taxes on you? Given the vacation-oriented nature of Maine, and the summer home crowd, one can see that this gray area offers many people who draw on state resources a loop hole from paying taxes that the state, justifiably, may be owed a pro-rata share on.
Arguably they should stop this use tax crap and just jack up property taxes and be done with it. But, that would kill their low income resident base, and deflate housing values. So...
Cheers,
-Andrew
who hates this tax, and most of Maine's taxes, but enjoys the debate anyways.