See, everything depends on one's perspective. Some are finding it difdicult to accept a brother in law sister in law becoming lovers;some are happy with it. Nobody is wrong here. Everybody thinks in a different manner.
For me, Jhanvi Kabir as lovers is not acceptable for various reasons. It will completely destroy Kabir's character. But I do understand that fans want ShreZain together as a romantic couple, but I really hope that it happens in another show.
As for other shows, I haven't seen those, but I am sure that the context was different in those shows.