Fairly sure Newfie is broadly used as a colloquial term of endearment in the rest of Canada, by Newfoundlanders and non-Newfoundlanders. There's just too many syllables

How about Newfoundland-and-Labradorean? It's funny that the only ones insulted by Newfie are the non-newfies.

I am a Newfoundlander and I don’t appreciate that term.

It is not. It is insulting and derogatory. Don’t use it thanks.

While that's not how it's ever been used in my life, I can accept that it's perfectly valid for you and presumably many others to feel differently.

Having grown up with so much predominantly east coast originating comedy, and around so many Newfoundland diaspora, I guess it never occurred to me that there was any real negative connotation whatsoever, beyond poking a bit of fun at some of the presumably antiquated cultural stereotypical differences via self-deprecating jokes that most people from smaller places have their own versions of and don't take too seriously.