I might be wrong, but I think people like Alan Kay and Christopher Alexander have in common that they:
* see that things can be done better (not as in upgrade but best);
* have a global idea/feeling of how this could be done;
* take a lot of ideas from nature.
And somehow I think they have a lot of trouble expressing the 'how'.
My take: we should take a good look at nature because this is closest to what we are.
For example the communication between objects could be learned from cells.
Maybe they're reluctant to pick "the" how, too soon.
If you're in a field from the early days, you probably have more of a pioneer or explorer mentality. Later come settlers, who pick areas for utility. Even later come residents, born and raised there, most of whom don't really question what is given.
This probably seems weird and frustrating to the explorers -- why settle so soon? Yes it seems comfortable and convenient, here, but there is so much left to explore.
That's how I understand Alan Kay. He doesn't want to sell us some snazzy next big thing. He wants more of us to spend more time imagining and trying new things.
Nothing wrong with looking at nature and trying to get inspiration from it (e.g. neural nets) but ever since we realized that flight was easier to implement with chemical combustion than by flapping wings, we know that just because something works in nature doesn't mean it will be easy to replicate for human use.
We probably won't, at least not at human-scale and not on Earth. Flapping wings don't scale; there's a reason you have to get to #12 of the heaviest birds list to get one that flies, at ~13% the maximum mass of the heaviest bird.
Alan was a Molecular Biology major in college and has stated before that the basis for OO messages was originally inspired by cellular communication:
> I thought of objects being like biological cells and/or individual
computers on a network, only able to communicate with messages (so messaging came at the very beginning -- it took a while to see how to do messaging in a programming language efficiently enough to be do messaging in a programming language efficiently enough to be useful).
My take: we should take a good look at nature because this is closest to what we are. For example the communication between objects could be learned from cells.