Could be a kind of traditionalism at work. I've seen a post on Bulbagarden where the poster wasn't convinced that Rotation Battle would have any worth, because it devalued countering (I get the feeling she meant critter-specific countering; as in specifically countering a particular set of Heracross, Salamence, Garchomp, Swampert, etc.), revenge-killing, switch anticipation, etc. The idea of I Know You Know I Know being integral to the "true" Pokemon experience is thus very heavily ingrained in them, and they may just not want to find themselves even slightly flat-footed in the new milieus.
3DS FC 1246-8792-4625; 3DS name: Skyknight; Pokemon Y name: Suzaku FS denizens: Tangela, Ivysaur, Maractus