It's a matter, IMHO, of the extent of the change.
For example, it was not hard nor 'jolting' to move from the old SOTW interface to the Cafe's. The Cafe's is certainly different than the SOTW's of a few weeks ago, and the Cafe has also been revised a couple of times (or more ?) since I joined there several years ago....but still 'similar enough' to not be unfamiliar.
The thing here is, as I see it - too great a leap in one fell swoop. To those who are very hip to constant techie www changes (called 'improvements' by some), no big deal maybe.
But keep in mind there are (were) many here who basically used the SOTW platform, in a pretty much unchanged state as far as usability and aesthetics....for a good decade-plus.