Why are some forms of fandom more acceptable than others?

This question has been really bothering me. Why are sports fanatics okay? Why are religious fanatics (of some types) more acceptable? Why are academic enthusiasts acceptable? I believe one of the chief reasons some of these practices are acceptable is because they are supported by governing institutions. Think about it. Sports are supported by the institutions in society that set order. The president of the US always calls the winners of big sporting events (super bowl, collegiate lacrosse champions, etc.). Our cities set up departments to run sporting events for the youth in the community. I work for the city of Hilliard Department of Parks and Recreation. I help run the swim team, and the local government has created an institution to support the sport--I never thought about that, but it is crazy when you do realize how much institutional support there is for certain forms of fandom. The early government and even the current government supports certain forms of faith. One of Bush's big ideas for policy was "faith based initiatives" to solve societal ills. I am going to take a guess, but there were probably no fundamentalist Islamic institutions that received a check from the government to carry out any programs to solve problems in society, but I would guess that there were more fundamentalist Christian churches that did receive checks to deal with maybe a poverty crisis in community. On the flip side governing institutions in Iran probably would support more fundamentalist Islamic institutions while certainly not supporting any Christian institutions. The state supports academics (cough::cough::well, most administrations have supported education cough::cough). The fans that we find odd are most likely not supported by governing institutions...trekkies, dungeons and dragons role players, cross-dressers, Japanese animation fans, etc.) This is not to say that the only forms of fandom that are widely accepted have institutional support; however, it is much easier for fan groups if their obsession is supported by the powers that be. It is possible that I will explore this question later and come up with another answer as to why some forms of fandom are acceptable.