This is true, but wouldn't it be more organized if it was condensed? Also, (granted I'm no business man) wouldn't the creation of a sub forum potentially attract more users with interests in the aforementioned topic?
As an anecdotal example, I work out a lot, about 4x a week. Weightlifting is my second passion behind school/aerodynamics. However, I am out of shape because I frequently enjoy burgers and ice cream and cheese cake and... It would be really nice to have some people to talk to about fitness and nutrition who are also interested in math and science. Maybe the intersection of those interests is too esoteric, who knows?