Hmmm. Where do i start.
Basically he was planning on making the place more attractive to actual racers (not boy racers - people who have a genuine interest in motorsport and who race their own cars) and didn't feel as though the Pit Stop (the most popular forum by far) was contributing anything worthwhile to the community - especially with some of the topics covered in there.
So he gave about 24 hours notice to Pit Stop users that that forum will be locked. 90% of the people were not happy about this as they feel that the GTF needed a place to talk about general subjects not related to Motorsport or Gran Turismo.
Once it was locked all the abuse/anger started - mainly in the Q & A forum and Kenji still defended his decision and basically said tough luck - if you don't like it then go somewhere else. So they did.
www.granturismox.net was created by two (?) GTF members so that everyone had a place to go (because they were scattered all over the place) and now that's the new home of GTF'ers.
There was also a bit of controversy (i think before any of this happened) after Kenji de-admin'ed two or three long time standing admins as well as a few moderators. The moderators all eventually resigned leaving Kenji in sole charge.
Then he announced that he was going to South America. He did so and when he was there he mentioned that he could have a potential buyer of GT.com down there. Sure enough a few weeks later granturismo.com was sold to a karting company (?) who have owned it since.
The GTF was relocated to granturismoforum.com (so it could still be called 'GTF') and he told everyone that it is still going to be a Gran Turismo forum. (long story - do a search in the forums)
So yeah. It's basically died down to three or four posts a week now which is a real shame but i'll continue posting there until he closes it. (seen as its the first forum i ever registered in)
Hope that explains the situation somewhat.
This is the short explaination too...