I think it comes down to personality, I think majority of people who supports teams are generally team players. They identify with brands, have a greater affinity to groups, policital party, community loyalty, more likely keep a long term interest/passion, likely to have a long term group of mates, favour team sports more - Football, cricket, Rugby, Baseball, Basketball e.t.c
Whereas Driver supporters would tend to be more independent minded, they are free thinkers. They identify with an individual rather than a brand , group or political Party, for example more likely to change political parties due to who is leading. They would tend to prefer or avidly follow Individual sports in most cases, - Boxing, Tennis, Golf, Athletics, wrestling, UFC, cycling e.t.c More likely to identify with a particular member of band rather than the whole band. They are more passionate and can take their obsession great levels, however would only sustain that passion as long as who or what they support has a chance of progress.
I'm not sure this works this way.
Me for example- I'm extremely independent person, even overly independent. In most cases I don't identify with any groups. I don't enjoy following the tradition. I value individual over group and I insist nobody should be forced to identify with the group just to strenghten the feeling of adherence. I always make my view on my own, not by following the group or authorities.
What can be interesting, my two favourite sports bar racing are football and cycling, two disciplines that belong to different groups in your view.
Despite my personality. I've always followed teams rather than particular sportsmans. But not with immediate effect. At the beginning I usually start to follow the battle of the frontrunnes and symphatise with some of them and against some of them, but not very strongly. Then I chose an outsider and follow him for a short time, before switching to his team. After the "switch" is done, I follow the team no matter what and the team is more important to me than any individual, but I still tend to wish very well some individual people outside my favourite team and I can switch my interest for them for a short time when they have a good chance of strenghten their reputation while my favourite team isn't currently in fight anywhere close to the top.
What else can be interesting, despite my route to support a team usually goes through supporting a certain person for a short time (I.E. I've supported Wurz for 2 or 3 months before I realised that I'm Williams' fan and the simillar story was in cycling with Christian Vande Velde and his team Garmin) and my choice of that person is based on the sound of his name, I always end to support the teams that are somehow connected with blue colour.
After all, I support the team very strongly.
It's possible that I'm only one of the few people who don't follow the trend you've described, but I'm not sure if this trend acutally exists.
Pity it's a racing forum, not psychological forum. I would like to investigate how the personality affects who do people follow in sport competition.