main point is that shashank is a much more practical man than his daughter riddhima who is very much sensitive and vulnerable......
we are all crazy AR fans so we want AR to unite but if armaan does not gets his memory back so it wud be feasible for riddhima to forget him and move on.....i agree armaan will fall in love with riddhima but will it be the same kind of unconditional love is not a surety........
so shashank is just being practical