Can't find reason to reject marriage proposal but family against it

[Unregistered]

I am a 28 year old girl in love with a 30 year guy. He belongs to SC while I am general category. My parents have been searching alliance for me this year, i too put forward the proposal of the guy whom i know for past 9 months. But they overlooked it saying that he doesnt belong to our caste. I told them that if i consider your proposals atleast you should consider the one i am interested in. He is educated a software engineer by profession his father is a field officer in a reputed bank, his sister is also in a bank and their family are well to do. i do not find any reason in rejecting him.