Kripa is neither selfish or immature. She is a sensble person, whose self esteem matters more than someone else's stupid ego.
Her being selfish towards her parents is a loose end on the part of the producer/director of the serial. Has nothing to do with her. I guess they are trying to concentrate on the main characters and parents are brought in and out of the serial according to convenience.
It is Angad who is brazen, selfish and mannerless. He is shown as a typical male with a king sized ego. I guess Ekta feels that women swoon over such MCPs. Well Ekta, just for info there are all sorts of women in this world. Some who do and others who don't. Times are changing. In real life chracters like Angad would be cast aside without further consideration. His mom and dad would have slapped him tight for his lack of manners and rudeness which he has displayed to the whole wide world.