The answer is simple, arrangers have always been designed primarily for the home market (Pro users are miniscule in comparison) who just want to sit down and play, and so are not familiar with pro keyboards and their actions.
Better keybeds dont sell keyboards in the home market only features, sounds, styles, easy play (Press a button and everything is done for you) and price, so there is no point in the manufacture spending extra on them.

Bill
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English Riviera:
Live entertainment, Real Ale, Great Scenery, Great Beaches, why would anyone want to live anywhere else (I�m definitely staying put).