so they didn't even ask why Grimm wants to meet Adhes...
He just wants to kill him. That's it
expanding on this, it seems like Grimm's main goal (or one of his goals) is to destroy dormitors as a whole. To remove the ritual by killing off the teachers (people like Adhes)
Dormitors are one of the bigger (public) reasons why the inquisition exists, to protect people from dormitors and their nemesis. Cutting out that part of the equation would in theory make it easier for infected to live peacefully without being prosecuted, but it's not going to be that simple
