Of course MT LLC's are used as a way to avoid taxes (not in every instance). If not for that, 99% of the LLC would simply evaporate. Others buy properly in OR for the same reason. Now, before you jump in and beat me up, we all do this all the time. We buy stuff on the internet and don't pay taxes despite the fact that the State we live in requires the collection of Sale Tax. We wait to make a purchase until we get to OR or some other State where there is no sales tax or lower Sales Tax but then return to our resident State happy as a clam. We drive from one State to another for lower gas or food or alcohol pricing all of which takes money from our home State coffers.
It's not necessarily a bad thing, it's just a thing. I moved my residency to SD from FL in anticipation of purchasing a new (to me) RV. That's a 3% tax savings on $100,000.