I think that people forget that Katya is just as much as a disciplinarian. Tony Adams came out and said that she gave him an absolute bollocking one day - but he admitted he needed it, and having been a footballer, she knew he would react to the hairdryer treatment.
So I don't think it's fair that GP is getting all of this blame, when other pros have admitted to doing the same.
I also find it strange the percieved "feud" between GP and Ranvir, when she admitted it lasted half an hour!
Ultimately, the producers need to find out more in their due diligence what each celeb wants to get out of the show, and how they like to learn - then match accordingly.
Some will be happy to be shouted at. Others will prefer a softly-softly approach. Some may be super competitive and want to win, others just for the exposure, others just there to have a bit of fun