And that brings me to the main topic of this post "Can personal relationships be conditional ?" and if I come to think of it this seems true in terms of Dev's relationships with his sisters. If I think from Dev's perspective then his love for his sisters was always unconditional, he never expected anything from his sisters but does the same hold true for his sisters, unfortunately No. I agree that Dev has made mistake of ignoring his sisters and that cannot be justified but did the sisters ever try to see the pain he was going through. Maybe Nikki was young but Neha and Riya were old enough to understand their brothers pain but yet instead of helping him come out of it they are blaming him for ignoring them. Just because he ignored them when he himself was broken have they forgotten all the hard work and struggle he had gone through so that his sisters can lead a happy life.
I hope the CVs at least explore this part with NIKKI because even though she was young she seemed to understand her brother better than her sisters.
This is just my POV, no offence.
PS - I would sincerely hope that the CVs instead of just putting all the blame on Dev, explore others as well. A relationship cannot be just one way.