Quote Originally Posted by Buffalobiian
I understand that they'd want to keep Stein away in his current state, but talking like that really shows where people stand. Despite how Stein's been portrayed as the most capable Meister in all of Shibusen, and even in his stricken state is still much trusted by Shinigami, in the end it's the Deathscythes who are Shinigami's most trusted guards.

It could just be Spirit's way to snap Stein out of it and get him to leave for his own good.
After Crona's confession they now know for sure Stein is deeply affected by the madness and more specifically also being driven crazy by Medusa. So, it would make sense to keep him away from Medusa.