I'd dispute that. Aikido is stupid simple what's highly complex is the way the simplicity is taught. There's a lot of beating around the bush in the way Aikido is taught but when you get down to the nuts and bolts of what is actually taught it's rather unsophisticated.
Alex,you have hit upon something very true!!
Not just Aikido,but Taiji,bagua,Eckey Thump,all taught(mostly)back to front.
The reason why judoka's have excelled at Aikido,better than Aikidokas themselves,is down to mainly one thing!!!
If you train for a high degree of dynamic balance,you can learn very quickly any technique(natural movement) from any art,and mix them up so they become no technique!
that's is what internal arts are...your own!!!
This twenty year technique idea is pure bollocks.
How many olympic swimmers,gymnasts,took that long to become good!
From a baby onwards we naturally learn through natural trial and error.Think riding bikes,climbing trees ect.
People can teach you techniques till the cows come home,but they can't teach you physical balance(purely internal).
Techniques are at best 1% of your art! 80% is balance,body unity follows along with proprioception,and working with gravity is what give you power.then it becomes very sophisticated and can always be improved along your life long martial journey!
Obviously you become more balanced practicing techniques.
But that is the backward slooooow way!! Plus you're thinking!making learning even slooooweeeer!
This why many masters,remain the master,instead of the pupil becoming the master,which can be done in months NOT years!
Food for thought maybe!!