With respect to kumud following DB's footsteps-
1) I think the fundamental difference would be their own personalities - with kumud the fighter and one who is willing to go down the wire if need be. Maybe DB was different.
2) What I understand from the FB and depictions from the show is that:
- DB did not really 'walk away' - she had a criminal husband who she got arrested (for what crime we do not know) and spent 14 years in jail.
- I also accept the fact that the above is a technicality - she is seperated and has no intention of going back
- in DB case, there was probably no support structure at her husband's place which kumud has now.
- we have also seen that VC & family has accepted and actually support DB's decision to remain seperated
- DB also seems to have adequate social status & respect outside of Desai household too.
3) DB has really been positioned as a role model for kumud.
So I think that while the concern of social stigma is a distinct reason for kumud, it is in relation to only if kumud is coming back.
On the contrary, I feel kumud is taking inspiration from DB's case (subsonsciously) - which essentially was about a fight against injustice and trying to change the status quo on your own at first.