Re: Convenience?
You say "blame Trump for local consumption" but in fact that is exactly not the point. US residents can attend a meeting in SF with no problem; the issue is whether all non-US-residents can do so if they wish - which at this time is unknown for July 2018. Hence, since the IETF is an organisation with no (repeat no) limitations on who can participate, the US is no longer a reasonable venue. This isn't a political choice; it's practical matter. Canada has visa requirements too, but at present they don't appear to be arbitrary or discriminatory.
Personally I've attended successful and convenient IETF meetings in both SF and Montreal in the past, but then, I don't have a passport that leads to discriminatory treatment.
Biting the hand that feeds IT
