Re: Dangers of moving from outside to inside IR35
If you could have found perm people and you were willing to pay them enough and treat them well, then you probably would not have needed the contractors in the first place.
It could be that some orgs judge that the value of clarity of tax liabilities justifies a higher perm salary which can now attract the right candidates for a position that would previously have needed a contractor.
Also, as almost all business decisions are capricious and stupid so it may just be a category error to attempt to deduce the reasoning.