Don,
I think you've just about nailed it! In my conversations with Yamaha US, they have explained to me that the costs were just too high to build these keyboards with flash Rom operating system capability and so only the earliest units had this ability. Now, because most keyboards are never going to have flash opereating system abilities, they are only supporting the chip replacement. I'm sure Yamaha feels there reasons are justified, but i understand the inconvenience we all share now.
Next, the need for a new operating systsem is largely caused by sophisticated users, like Scott, You, and Uncle Dave as well as many others using the 2000 in ways the engineers never dreamed of and so the need for a newer system developed. For hundreds, thousands, even more perhaps, the need for this operating system update may not be necessary because of the way it is being used, but Yamaha will cover the costs under warranty for anyone wishing the upgrade.
I thought this explanation I received could be helpful.
George Kaye
Kaye's Music Scene