This sounds great in theory and I would totally agree (in theory), but my experience has been that it's the PMs or executives or higher managers that make the decision, regardless of what the engineers think. In fact, most of the times I've seen sprints pushed back on it ended up in bad feelings and unintended offense taken by PMs. In the end nothing chnages, except that the engineer who "stirred the pot" loses favor in the eyes of management.
If it was up to each developer or developer team, I would agree, but in reality it rarely is.