Give up days, extend, or not do it. There's 3 options not just 2.And exactly why this situation was part of the survey Disney was soliciting input about.... would you be willing to give up days or would you extend. This idea of contention is already well understood by Disney.
I don't know about the rest of you, but "extend" is frequently not an option. If it was a long weekend trip turning into a week long, perhaps. But, at some point, a week for myself, that's really it. Extending would mean giving up some other vacation trip at another time during the year.
That's the same sales pitch DVC uses. Buy your Disney vacation and give up going other places (mostly). And they sell a ton of those. Maybe it will work.