If you ask me and nobody is,

its all down to badge snobbery.
GTD drivers simply don't want to be classed with the peasants as a lowly TDI.
Like Penguin has said, they bought the top of the range Derv which VW class in the same category as the GTI and R. So I can see their point. I would probably feel the same.
However, they keep bleating on that the GTD and GTI are virtually the same so as such, most if not all the posts should be going in to the MK6 section as opposed to the specific TDI section. So does it really matter at the end of the day?!
Its a service with a wealth of information offered free of charge. If folk are complaining in a roundabout about way about this then its a bad day.