The Dumb----- at Yamaha marketing make sure they don't interfere with Genos sales....Actually they are missing the boat because putting aftertouch on a SX-900 would cost very little and make a lot of us happy. It would not cut into sales for Genos, IMHO.
Thats how things work..
With all these companies, if you want aftertouch, you need to buy the top end model
Same goes for extensive real time controlls (knobs and sliders) only the top model..
Yamaha takes this one step further..
Its high end sound features (sa2, ensemble, revo) only high end..
They want you to buy genos/montage/pa4x/kronos/Fantom and not the cheaper keys..