[danda012]

In my opinion it all stemed from a few events:

Firstly Grace in BB7 (was the birth of GET (name) OUT chants at evictions)
Secondly was the events of CBB5 with the Jade, Danielle, Jo and Shilpa controvesy
Thirdly was the fact they enforced rules TOO tight at times afterwards
Fourth was the selection of HM from BB8 onwards
Lastly was the new generation of voters. Even in BB7, there was signs of the future decline when Suzie who did nothing survived several evictions.