Letting knights demount would have been a lot more work (to code, to make the models and skins, animations and the like) for them for very little benefit (they reckon), and I think that's fair enough.
There will be dismounted boyars and various other dismounted [insert cavalry], but you can only get them by training.

Buyt that's not a big enough reason for me to drop the game altogether
There's been various other stuff that bothers me as well. I just don't like being misled. It's obvious that CA raised a smoke screen of confusion to make buyers believe that mount/dismount was back.