There have been several situations in the last 12 months where the desire to go to the US (and Vegas, in this case, for conferences) just isn't there, as we are hearing so many terrible stories about travellers being harassed or unwelcome when trying to enter the US, due to the current Government. Anecdotally, this has been the reason I've heard from Canadians who are also considering travel to the same conferences.
The very year we declared a trade war with all our friends they stopped coming by to visit!
The only surprising thing here is that anyone is surprised.