Honestly, the flip is fine, it had to have been this way or that way. I don't have any much attachment to the character. I do wish, however, they had maintained a balance, keeping in mind that this is a daily soap, & things could change, OR they might need to extend the show indefinitely. 
So pre leap, couple of times, i didn't like DK. Once when he watched Vik Mannat on his birthday. It was an intensely private moment, & he didn't know them very well. I found it creepy. Second was when he left Vishakha out in the middle of the wedding.
Why I am saying this, is that it is still possible to show him as a little off even pre leap. So that people can connect with this villain era.
Post leap, they created such a strong bond between him & Dua, that we thought it would be difficult to break.
Also they created a weak beginning for Duvik. So this whole confusion went on.
While I respect the actors opinion about the tracks, fact that DM were never married meant there was a loophole for Vikrant to enter. DM could have been married..continued the same way with no marital relations. Mannat also was so staunchly for DK, that I too thought she would choose DK, even if for Dua.
The writing is short sighted. It's like with every track they paint themselves into one corner. they need not have made Vikrant so reactive, pre leap. They are doing the same thing now, making Vik vulnerable as Abhi.
Aisa hi hai, inka style.
Brother killing brother? When the first episode shows a mother attempting to kill her baby, what can one expect? But the ARS track was done much more classily.
Now they are just pulling on till the plug is yanked off. 
702