I don't see the issue of being a "plastic" lying in whether you chose the club or not, rather how you support the club. My best mate is a self confessed plastic ManUre fan and he's never been to a game and barely knows when they're playing, I'd say that's a long way from anyone on here. EDIT: You could argue that choosing a club means you're more likely to be a plastic, but I don't think it's the sole decider.
I think the OP causes some confusion by in effect asking if having no connection to Leeds but following them makes you a plastic. I have friends that follow Prem teams, but never go and yes, they're plastic, but I know people that don't go to City because they've moved, but they're still fans in my eyes. Perhaps plastic's the wrong term for those that latch onto a club they've no connection to, but whatever you want to call it, I still feel my comments are valid.
I've not lived in my place of birth (Hull) for 27yrs. In fact I lived in Leeds (Horsforth), amongst many other towns/Cities on my travels.(Cambuslang, near Glasgow, is another) My children were born in Oldham. My son who is 8, attends his teams football training in Hull City strips.Is he plastic? Or should he support Oldham Athletic?