Why did they make Dragonball GT?!?!?!?

Ok guys I have a couple of questions I cant seem to figure out, first of all I just watched Dragonball GT a second time (the whole series) and I was correct the first time, it is aweful. There are many things I hated about it so I have to question the creators and why they screwed up such a good thing. I have alot of questions and if you can answer any of them awesome. Why did they change Goku's Uniform (gi) when the orange one was his symbol since Dragonball! Why was he turned into a kid again (I know why in the series, but that was a STUPID idea)!!!!!!!!!!!!! Why was it made so childish!! Why was it all about Goku when in DBZ everyone was around equal power, in DBGT it was like Goku was the only hero!!!! Why did they pretty much write out Tien, Krillin and Yamcha, I know they were behind in power but they were still great characters. Also,even though Tien and Yamcha were fully grown when Krillin was a little kid why the **** did he get old and they didnt?! Yamcha looked 30 when the series ended, Tien looked the same as in dragonball and Krilling looked 60!! ANYONE AGREE?!