It has a lot to do w/ leaving a bad taste in one's mouth. Imagine screwed w/ shows like Bandini & Jyoti (interfering w/ the CVs and dictating story content), and since going from NDTV to Turner, was a lot less patient w/ shows and demanded instant results. And since it got it in some cases w/ KMH2 and GkD, they expected that from all shows, so if a show didn't show up in the top 100 after 3 weeks, they'd start interfering.
Take Rakt Sambandh. The story started slow, and was about a blind girl who was tricked into a marriage w/ a eunuch, and who discovered it and started getting tortured by her sasural once she had discovered it. Oh, and the sasural was also behind her father's murder. She attempted to cause an accident to kill both herself & her hubby, got back her sight after treatment, and infiltrated her sasural under a new identity, and caused enough dissentions among them that in the end, she could send them to jail. This was in January.
During this time, that show had TRPs >1 - it started low, but shot high after she regained her eyesight and started waging a war on her in-laws. After January, they moved the time slot from 10pm to 7pm, and TRPs tanked. To make things worse, the CVs made it a saas-bahu show for a while, and after a bit of that, pulled the plug. The original USP - about 5 sisters w/ different struggles - was long forgotten. Aslo note - after the first 2 months, there were hardly any promos for the show from the channel, even for major events like the lead gal's 2nd marriage, or the original lead guy's death.
I just mentioned RS. Imagine started off some shows w/ low following, like AkBA, and then interrupted it by killing the lead and inserting Dolly Vrinda. So obviously, people who follow that are pissed. Bandini & Jyoti fans are pissed by the endings those shows got. So people who didn't like what Imagine did to their favorites have left the channel in droves.
GkD & KMH2 are lucky that their USPs were TRP +++ for them, and so they didn't have to change it. I think they'll continue to do well. But other shows that didn't give instant results have gotten the shaft from the channel. Given what it is now, they should switch to an all Reality show format.