One possible reason is that a person can have beliefs that don't completely align with a given platform.

Another reason could be that it is easier to obtain emotional distance on a decision when you're not personally involved. Believing that something is best as an abstract policy doesn't always make it easy to believe it is best for you.

A third possibility is that he does believe that the market should decide, but that he also believes in taking full advantage of the system as it exists today.