Aye, the influx of foreigners with no connection to or understanding of the club does take the piss a wee bit. But then imo there's a difference between foreign, or non local, fans who support a team for a genuine reason, be it the style of football, the philosophy, the history, the players, whatever, and foreign fans who just latch onto them due to nothing but success. Exactly as there is a difference between local fans who love the club and support them through thick and thin, and those who claim to be lifelong supporters as soon as the club has a bit of success.
That depends a lot on who your local team is. I doubt some people who live in Milwall will be gutted to have missed out on match day experience, when that experience often involves sitting next to a load of skinheads looking for a fight. Ultimately, you miss out on match day experience by not supporting a local team (unless your cym of course

) but not all match day experiences will be equal.
Not sure why it's ignorant? It's the same point as above - at what point does a team become your local team? Utd is my most local league club, but when living in Altrincham there was non league Altrincham FC (who I did go to watch a fair few times), and back in Croft and Warrington there were amateur and semi pro local clubs. And I'd guess there were probably non league / semi pro clubs more local to your dad than Chelsea?
Ultimately the local club factor is important, but everyone defines their locality differently, and a big club like Utd or Chelsea will have a much larger local area than one like Altrincham FC or Spotted Dog FC (the team from Croft). As long as you make a genuine emotional connection and stick with the team through thick and thin it doesn't matter that much imo.