Are you forgetting that Corporations get taxed, you have to be careful not to trigger anti avoidance legislation, and being a consultant offers much less job security and benefits than employment?
This is going off topic.
Actually I don't entirely agree that self employment is more risky. I used to think that way but being in Financial IT as an employee I've been through many rounds of redundancy. An employee can get tapped on the shoulder at any time, just as a contractor can have a break clause executed. The difference is that the contractor will usually structure their working life and finances around that possibility while it can be devastating for an unsuspecting employee.