TOR was hacked by the US government earlier this year.  While hotels and airlines don't have the tech knowhow to see what you are doing online with TOR, the government does. Betcha dollars to donuts that any active TOR instance on a plane is 100% recorded and spied upon by Homeland Security or the TSA.  While they probably don't care that you are on a fuckboard, it still seems to me that it would probably be better to wait til you arrives at your destination before logging into TER.  Just IMHO.  Do what you will young padawan.

Read the holy bible or Koran.

for the flight attendant to unblock it... maybe you can even tell her you're an air marshal and after you buy her a drink she'll want to see if you can both fit in the lavatory  

I recall back in the days before the Internet, Marriott was about the only hotel chain where you couldn't buy in-room porn.  So at least they're consistent.  It's a pain in the ass but since they own the hotels I guess they can do what they want.  Any you can choose to stay elsewhere.  It's not as if in most places there aren't plenty of hotels to choose from.

but then again, even if they did block TER I have "personal hot spots" on both the phones I carry. So logging into TER still wouldn't be a problem.

Truth be told (LOL!) I haven't been in a Marriott for ages.  But there was a discussion here within the past few months in which someone said they'd been blocked from logging in there.  And it made me recall that back in the day you couldn't order any porn from a Marriott room.
Just one more reasons to hate thumpers, no matter what version of the bible they are thumpin'.

Let's not be putting mis information out there, There is already enough bad information floating around. Over the last couple of years, I have well over a hundred nights staying at various Mariott  Hotels  in two or three different countries, and I can't remember ever being blocked from accessing TER.