Well he said "the closed nature of Pluto", not "the closed source of pluto". And considering that people were lucky to get any kind of response on the pluto forums at all, I think he has a point. Another example of "the closed nature of Pluto" is that we have to almost reverse engineer most things to figure out how they work. Not a healthy situation in my opinion but apparently that's how Pluto chooses to do these things.
i tried to get in contact with them 2005 and multiple times in 2008. Pluto was always very responsive and helpful to me. And looking over the old forum it looks like they tried hard to give support with limited resources.