Maybe because he couldn't find any reason to prefer Ron Paul over Romney? The failure to prefer Ron was basically a direct violation of their mission statement - so why should anyone believe that a statement they defied then is meaningful now?
I also have a personal axe to grind against FreedomWorks, concerning a particular domain name that is very specific to an alias that I and only I have extensively used that they've been squatting on (and done nothing at all with) and refusal to respond to many inquiries about it over the course of several years.
Why they're sitting on a domain name for over seven years that is only meaningful to me, and keep re-registering it every year, and never return any communications about it, is a complete mystery.
Ironically, under the alias that they're squatting on the domain, I did more to substantially advance the cause of liberty than FreedomWorks has done in its entire existence (for those who remember, this is Brat/Cantor related).