They already know that a) MC is an unique existence, and certainly far more powerful than anyone on their side, hence why they need him, b) MC is extremely hostile and willing to kill if provoked, and c) MC lives within a barrier that not even royal treasures can break through.
So what exactly is the fucking point of a public bounty? Who the hell are they even trying to attract? If there is a bounty hunter skillful enough to break into MC's home and either deal with him or capture his woman, then why not just recruit that guy instead?
It would be fine if they tried to get the girl using like secret royal spies or some shit. At least that would mean they think they can covertly get past him. But making your intentions public knowledge is beyond braindead.
I know this isn't exactly high level literature but holy shit, the author didn't even try. This conflict is so fucking forced.