Daksh ne Brhmaji ko koi vachan nahi diya tha, that he will get Sati married to Shivji. He did the tapasya to get her as his daughter because Brhmaji's told him to do that. He was egoistic, arrogant & revengeful towards Shivji from the begining. You are repeating the same words even after being answered. May be I am too dumb & ignorant to understand, such an intelligent question, which is already answered again & again in the show.
Are tabhi to usne devi shakti ki tapasya ki thi, taaki unka vivah shiv se ho sake, 4 the betterment of the world. But now his ego ha sgrown up such that, he thinks shivji is nothing and just want 2 take revenge from them.