Their partnership produced sparks together with Perry as an anchor but that was a long time ago. Now they are left to their own devices, without management nor a strong songwriting partner.
With Cain's interest in religion expanding maybe Neal simply has too much time on his hands making him trigger happy with tweets like these? A passive aggression of sorts for having to sit at home when he wants to create and tour much more than Cain allows him to. Cain, on the other hand, knows the value of his stake and is hesitant to let go for monetary reasons, creating this forced co-existence when both parties would be better off on their own.