I think the key is, do you like your favorite just as much when he/she fails and when he/she succeeds?
This point flirts with that all-important distinction of fairweather fan vs. true fan.
I must stress, fairweather fandom isn't necessarily a bad thing. Everyone likes a winner. In fact, it can be good in a way- and here is an example. You see it all the time in team sports- when a city's team does well, suddenly everyone is hanging signs and watching/attending games. They help fill up the arenas and pump up the surrounding atmosphere. True fans stick around even when the team does poorly- and they are essentially the life-blood and support of this team, as they keep buying the tickets and merchandise. But the fairweather fans come in droves when the team is winning and help to provide that electric atmosphere that is so infectious during the playoffs. Eliminate them from the equation and you still have an enthusiastic crowd, but it is much smaller.
Translating this to skating, or individual sports, it's a little trickier. I'm sure most athletes would much rather have the fans who stick by them through thick and thin than the ones who are plentiful when everything's good, but vanish when the going gets tough. Sort of like how friends work...who are your REAL friends?
In response to R.D.'s question about fandom: I feel like I have a need to reply to unfair criticisms about a skater if I have more background knowledge about them (most likely because I liked them to begin with to read up more about them) and someone is spreading horrible rumours about them, especially if someone is trolling and writing crappy posts just b/c they really dislike someone. I'm not sure if it has to do with fandom per say, more like having to do with not being able to stand unfair comments.
Well, this is a fair point. I don't have to "like" someone to feel an unfair comment is being made. I do this a lot as well.
I was really getting at reactions to more mild criticisms, say perhaps "she's slow" or "she does nothing for me" type of comments. Not the inflammatory type. I see strong reactions by fans of some of these skaters who are being criticized mildly and I want to know why they do it- the psychology behind why they feel the need to be defensive.