Skills Gap
tbh I think that if the traditional reason for using contract resource is reviewed and validated there shouldn't really be an issue.
Contractors are traditionally used where shortfalls in resource of specific skillsets are required at short notice. If this still applies, all the contarctors out there need do is raise their rates to cater for the loss due to IR35. If there is still a demand for the skillset then the market will pay, or failing that, it will in turn boost the focus of the employers to focus more on planning and employee development so that the need for contractors is diminished.