Well, I think it's a bit too simplistic to claim that people who need to follow specific players don't like the sport. Usually my interest is divided between three sports: tennis, cycling, and ice dance.
I think I love all three, but still, my interest will fluctuate from time to time. And usually, it depends on whether there is someone that can feed my interest or not.
I used to be really crazy about cycling, but at the moment, to be honest, I don't really care much, because there's no one that I like enough (apart from Andy Schleck maybe, but it's more like a slight crush, I find him adorable but I don't think he's that great a cyclist so it's not enough).
At the moment, I am really interested in tennis, because Ferrer is someone that I like as a guy but that I also admire a lot, and I love both the personnality he projects and his tennis. Plus, he's doing well at the moment.
As for ice-dance, I'm following it more closely than cycling, but not as closely as I once did. Since all my favourite skaters have retired, and because it also coincided in my opinion with the return of a very classical, unimaginative approach to ice dance, I sometimes cannot bring myself to care much about the competitions anymore. Still, ice dance is not only a sport that I watch, it's a sport that I've practiced for 10 years, so the fact that I'm losing interest from time to time when no skaters can instill much enthusiasm in me, does not mean that I do not truly love the sport.
Sure, I see your point. Wasn't my intention to imply that losing a bit of interest in the sport when a player you like is not riding good momentum = not loving the sport. Maybe I interpreted his/her post wrongly, but saying plainly 'don't care anymore' sounded a bit rough. I do know people that gave up on specific sports as soon as their favourites retired, or started to greatly decline though. Like I said before, one can lose interest in a sport from time to time and it happens to almost everyone, but if you truly do like it a lot, it shall come back for sure.
You make a very good point and I think in some cases the bond with it will be way greater if you actually practice or used to practice it. Again, back to my previous post, I've lost some interest in tennis many times but it always ends up coming back eventually. I know I would still watch it and play it casually even if a time comes were I don't like any player, the great memories both playing and watching great matches would pull me back!