Surely the answer lies somewhere in-between, that we must rest, and we must move, and the amount of each must be relative to each person and activity.
I would prefer to see studies not just trying to prove things bad (we have enough of those), but focuses on what can be proven to be a positive, for example, the optimal mixture of activity and rest for different people and situations.
For example, in addition to "sitting may be bad for your heart" (while necessary and important), I would like to see more of the studies that say "for age group , occupation , walking for interval followed by resting for interval increased or positive benefits".
Since we automated a lot of manual labor, maybe the next big thing is automating sitting all day so we can get up and walk around.