Supporting a team is a matter of heritage and regionalism. I support Sporting because my father and my grandfather do it (the latter since the 1930's) and also because I'm from Lisbon. It's just weird to me that a guy from Indonesia or whatever supports Liverpool. The only connection he has to that club is from some games he saw on tv and he probably liked the players from that specific era and not exactly the club itself, its founding principles or its history.
I mean I also admired some teams in the past due to their style of play or the stars they had (late 90s and early 00s Inter, Milan, Juve, ManU, Arsenal, Mourinho's Chelsea, the galaticos Madrid, the Guardiola Barcelona and so on) but I never considered myself a supporter as I didn't really care if they won or lost a game. And once those players left, I really didn't watch them anymore.