How much do MIDI DIN ports cost to add in? There have been a few budget, light weight, 73 key'd pianos released recently that would have been perfect for a bottom slave board, but alas, no MIDI ports. Surely companies realise the market they miss out on by not including them?
I don't know about cost, but it seems like keyboards which are aimed at home users rather than gigging performers tend to have USB-MIDI only, so I guess Casio isn't targeting these new CDP models at gigging performers.
It's no big deal to me, because I'm strictly a home user and I usually keep my keyboards connected to my desktop computer via USB anyway, so my computer does all of the MIDI routing and processing that I need.
But I know that some home users won't seriously consider adding a 'board to their setup unless it has MIDI DIN ports so they can directly connect it to other equipment.