The unserious kooks will always have the same ability to vote against the next person the majority of their party might rally around.
Keep in mind that a lot of the reason Republicans support McCarthy is because the job of Speaker entails a whole lot of technical work behind the scenes, organizing schedules, understanding the rules, etc, that few representatives might possess.
If the unserious kooks might vote against anybody, then they might as well stick with the guy who they think has the skillset to do the job well.