Aside from the "buy new" factor, a surprising number of people believed that it was not possible to view digital TV on older sets at all and some dealers didn't exactly rush to disabuse them of that notion. Even the media often got it wrong as well
. Making sure nobody HAD to buy new was a condition of the switch to Digital but of course it would have been easier just to plough ahead regardless. It's a long way from 1926 but arguably the move to Digital Broadcasting was almost as significant.
Dave