Firstly, if you're a person who lost her life, you'd obviously curse people in anger without thinking of the repercussions. Secondly, I agree that the ancestor was an asshole, because of the curse, Salvatore was forced to endure rejection from his family, all because he was born a male. Third, he isn't cold and aloof, he just doesn't respond in fear to certain scenario, because the ancestor took away his fear, in hopes that he can find love
I think the curse wasn't thought out well either but I think Salv is being cold for a psychological reason, probably that Crescent is monopolizing him out of "love" and he probably has a twisted sense of love due to that, or he hopes that by distancing himself he can better get a confession, orrr maybe he thinks distancing himself can protect wolf guy from something he probably doesn't want to be involved in (as he actually says in the manhwa). My two cents.
But I don't like the red cloak or his ancestors. He's cold, an asshole and aloof. He produces not pity from me. And How can you curse everyone for one being's action? I feel for wolf and his family. ╮( ̄▽ ̄)╭ Crescent and gretel are assholes too. How wolf doesn't get hurt more because he already has feelings for the cloak.