I am not certainly of this, mainly because I don't design keyboards, but my guess is that these things are on the drawing board for a couple or even few years before they are released. Example - Motif -( classic ) released a couple of years ago, used Simms for ram memory. The ES uses Dimms. Computer technology progresses, but the design parameters probably reflect what was current when our "latest and greatest" boards were still in their design infancy.

AJ