Arshisfan, it's not merely a case of hating the first option. Even the second option would have to be done with Sultan dead and his son forgotten. Seeing him or his son in any further track would make it worthwhile to give up on the series.
And Aryan would be a living reminder of Madhu's cordial association with the boy's father. We'd end up needing RK's child from a previous relationship to turn up and be placed in Madhu's parenting to balance that. A heck of an unfair balance it would be.
You can't show a couple tending to the child of a man who wanted the wife and was maliciously and viciously envious of the husband. It would be repugnant reminder to the audience of not only the kid's father, but of the wife's having supported that person against her husband.
Both father and son have earned a degree of mass-audience antipathy that the series has no leeway or time to get past.
This was a character for which they tried very hard to make RK look villainous, so that they could make him parallel lead and then main lead.
Thanks be to the mass-audience that they completely rejected that effort, and backed RK even despite the way he was suddenly being portrayed.
And regarding other tracks, you're right, any attempt to be provident by fledging out tracks for the supporting characters would be beneficial for the series and the leads and give them some time off. But it doesn't work here, because this series has always been about Rishbala. Mass-audience doesn't seem to have any interest (as per ratings) in watching any tracks except as affecting the lead couple, with the latter being the focus.
Well I guess for me all is a matter of a nice execution and solid arguments to make a track work, when Sultan fell for Madhu he didn't know that she was his brother's wife, just like Maan in geet didn't know, not that I say that Sultan was fond of RK but at that time he wasn't portrayed in the bad way he is portrayed now, well I never liked him near Madhu, especially when he touches her even as a friend, for me Madhu belongs only to RK in every single way, I might even say that Rk is the only one who has the right to make her suffer just as he himself gave to only her the right to break his heart if you still remember their wedding day at the mandap. So I just say that there could be many options but for safety even then i would go with Bhai's death