I think its because this forum is a place of connection and talking to other people allows you to learn from them. Speaking for myself, there have been numerous instances where I've read forum posts and modified my opinion cause the person I was talking to had a strong point. 
I think its normal for people to have issues with a show and still watch and comment on it cause no show is perfect. I have many issues with the show and some of them are just because my expectations are too high for ITV. The reasons I still keep up with it are these... 
1. I've been a fan of this show since 2013 so that's a long association for me to just cut off. I've seen their cringe or boring tracks and I know that they do bounce back so I have that hope. I know that for tracks that I really hate I can just ignore them and come back when the better plot is here. 
2. I love Akshara, Naira, and Sirat. Akshara as a mom to young Naksh was what connected me to this show. Young Naksh was the cutest and Akshara was a fantastic mom who stayed true to her roots as a Maheshwari while being a Singhania bahu. Naira is my sherni and Shivangi is my fav (I've watched her since her stint in Beintehaa). Naira's made mistakes in every role she's played (i.e., daughter, sister, bahu etc.), but she never let anyone crumple her independence. She knows that she's a force to be reckoned with even when she's alone and I want that type of confidence. And Sirat is the weakest of the three - her plot wasn't developed much and emotionally, she lacks willpower and confidence but that's why I love her. Sirat wasn't a Mahaanta ki Devi. She was an insecure human to whom I could relate. I found her love for Kairav and Akshu to be earnest and beautiful. And I truly believe she respected Naira and that takes a big heart. References to all three make my heart leap and so, I always check on Twitter if a reference has been made before watching the episode. 
3. Huge Harshad fan. I found his chemistry with Sushant in Kis Desh Mein Hai Meraa Dil beautiful and essayed the roles of Raghav and Aditya Hooda, in Dil Se Dua and Bepanaah, to perfection. Seeing his promo for the show, I got so excited. 
4. I watched Pranali in Barrister Babu and I was shocked to see her here. Those two roles could not be more different so I wanted to see if she could pull Akshara off (she did IMO). 
However, if you truly detest a show, then watching it is a waste of time. And commenting just to spread hate is stupid IMO. 
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