I think PPL/IR have done most of the work to kick off the most recent movements, by getting in at the right places.
However, I still believe that the ultimate "lubricant" for a more accessible private IR has been the stampede to the FAA option.
Yep, exactly right.
Moreover, as someone else commented, it is to AOPAs shame (and for all I know some or all of the other representative bodies) that they seem to find it difficult to work with each other, and for this reason GA in all its forms have long been seen as ineffective lobbyists.
However, things maybe are changing. I commented some while ago that AOPA's web site was simply awful. They have now changed their web site and when I have 5 minutes I shall look to see with interest whether I might now feel compelled to join after many years of not renewing my membership.