Yes, RK's are a bit more prone to stuff moving around in cabinets and fridge. But, there were many times that the junk in our medicine cabinet in a rear bath trailer ended up in the sink or the floor when opening the first time after arriving in the woods!!!
Like "Old Duck" mentioned, the road is the main problem, more than the kitchen location. Also, the rear overhang can be part of the problem. More behind the wheels, and more up and down at the rear bumper.
On our newest trailer, with the fresh tank at the rear of the axles, and a relatively short rear overhang for a 34' trailer, we don't have too much of a problem. We do travel back roads a lot, so we see rough, gravel, or rocky roads. Worst times has been on highways when hitting extreme bridge approaches, or the "temporary" ramps found on hwy repairs!! Sometimes you can't slow down enough to prevent a nasty shock to everything.
Some of the rear kitchen vs other plans is, to me anyway, just like the generator, hitch, truck stuff that we have the "professional" rv.net police around to take care of!!!!