Read a lot of opinions here that other characters are being butchered to cover up Anupamaa's mistakes. And since her actions were not garnering sympathy, the trajectory of characters like Anuj is being ruined.
But the premise of this contention lies on the perceived opinions of viewers. Given the mainstream success of this show, I'm quite sure that majority of the viewers who are contributing maximum to the TRPs, know very well whatever Anupamaa has done and support her DESPITE the same because her depiction echoes what they think. Most of the viewer base that is actually crucial for them, remembers everything she did and doesn't find fault even when she errs like the instances of 15 day challenge or running to Shahs at the drop of a hat. She will keep getting sympathy and other characters will be criticised, whatever they might do.
It may be jarring to see her mouth certain regressive dialogues but the makers are depicting the mindset of people quite accurately when they show Anupamaa repeatedly going back to Shahs. They along with the channel are well aware that toxicity sells and that people want to watch the female lead crying, being tortured, sacrificing and the likes.
Yes, fluctuations in TRPs do lead to some changes, but the character of Anupamaa has had sustained popularity and never really changed. She is glorified even with whatever (few/many?) wrongs she has done and this may not be the primary objective behind tinkering the other characters.