i think it's a reaction (over?) to the point and shoot digital camera trend -- folks are so used to seeing everything, near and far, in sharp focus because p and s digital cameras are pinhole cameras, pretty much...or at least have the same DOF of a Minox camera.
So when they see actual depth of field effects -- selective focus! -- they think it is something nifty and cool and want to do it more.
So they do. I've even seen NY Times camera reviews refer to selective focus as a "professional" effect, as if it weren't something that everyone was able to do at one time.
I like using it to shoot portraits with my Rollei and a Rolleinar #1 -- makes a nice effect.