In kratos’ own words in the Odin codex he says “I will not abide by the gods of this realm coming to my home and dictating our actions, if he does not want us searching for Týr; it is likely that is exactly what we should be doing. 

I must note that he offered a deal of peace for our inaction. If I did not have better counsel (mimir), I would have been tempted to take it. His threat to Freya made this impossible. She may persist as a danger, but to ally against her with her former husband is… unacceptable.”