I think the reason people are "upset" with Teoscar over Mullins (aside from the obvious - performance) is that Teoscar outside of Toronto isn't a hugely popular player. Trout and Judge are well known. Them making it, even if the numbers didn't justify it (they do), would make sense. Hernandez is just as much a no name as Mullins is so it's easier to question that one.
To me, Winker over Betts is more disappointing for the star power reason. Betts is way more known but yet somehow wasn't voted in. Neither was Muncy, so maybe LA fans just don't care. I think the AS game should always be a popularity contest. Baseball needs to showcase their most known and charismatic players. If some no name shmuck was outperforming Tatis, there's no chance I'd want that player in the game over Fernando. In the case of Hernandez versus the field, everyone in that spot is relatively unknown outside of baseball circles, so it can be more of a debate.
Either way, as others have said, if Canadians spamming the AS votes help with attracting players here, then even better. It may even slightly override the whole "you have to play in a minor league or spring training park until the end of time" thing going on right now.