So after she saved Seoul (and by extention the world because of the scale) over and over again, those ungrateful bastards now wants to backstab her? Are they morons? What are they planning?
Closing her restaurant? Wouldn't stop her from still being a target. What's worse is without the restaurant she wouldn't have the incentive to keep collecting ingredients or keep the public order for her business.
Moving her somewhere far from Seoul? It's basically the same with the above about her having no restaurant (because there's no customer), plus now she's too far to help Seoul.
Hiding her? Those that targeted her are smart; they can easily decide to attack Seoul to lure her in. Also no restaurant.
Also, shouldn't these morons realize that aside from being the strongest guardian she is also the biggest deterrent that stopped most of the bad guys all this time? That without her Nidhogg and lots of other monsters would have destroyed Seoul already?