Take Amazon for example. If they went from the design 5-7 years ago straight to the current design, there would be uproar, Stock price dip etc.
The incremental approach allows the site owner to both roll back bad ideas but also condition users into where the design is heading.
(Correction: not Conde Nast) The owner, has a plan, which is clearly not inline with the current Reddit usage, this is not the approach to get to that goal.
I am struggling to think of big drops like this working, anyone?