I agree wholeheartedly.
The foundation of everything I know about programming began with Playmaker. I can now accomplish nearly every strange task I set my mind to in Unity in general... but I still use Playmaker for almost anything even if I have to make actions from scratch. The logic is easy to follow and represent and the PM framework is a marvel of power/practicality-meets-intuitive-UI-design.
I also think the power of PM as a surprising educational tool for non-programmers cannot be overstated.
Looking back, if I knew what I would be getting when I purchased PM, I would have paid five or six times the asking price.
Cheers to both Alex and Jean.
If I have one worry/suggestion about PM's future, it would be that much-appreciated additional functionality seems to be coming in the form of much less-intuitive extensions that feel a bit out of place with the rest of PM. I'm thinking of Arrays and the 2D extensions, in particular. The extensions Jean has put so much work into are quite usable, but don't quite have the same surprisingly-easy feel to them as the rest of PM, so they do feel tacked-on when the features themselves seem to be of core importance. Native array variable types within PM, for example, would be a godsend and a time-saver.