In my POV, Shagun love Aadi as a perfect mother, so that he love her back in this way... he is completely her son. In his heart, the place of a father is occupied by Ashok (only 50%) . he is watching Raman thru the eyes of Shagun. so he hate him. oneday if aadi realizes who is raman n ishita, he wil definitely love them. but to Aadi, his most favourite person is His own Mumma only. Ishita is always his step mother to whom though he wil giv respect n love as A step son.
Ruhi saw Raman thru the eyes of bhalla, so she respect him, then thru the eyes of Ishita,so she love him,and atlast he saw her papa with her own eyes, thus raman became her most favourite person. She was a motherless child frm her birth. So Shagun is just familiar woman for ruhi. Ishita is her real mother. none can replace.
I dont wish to c raman's victory in the custody case of Aadi. He is Shagun's son, not Ishita's. So he can't live under her care bcaz nobody is equal to the mother. So I prefer Ishraruhi family without Aadi who must be with his Mom Shagun & his 50% papa Ashok (hop he wil turn postive n 100% papa - I think so sirf Aadi ke liye)
PS: I used here the words "mother" "father" not in biological meaning. It have PSYCHOLOGICAL meaning