JW, why don't you try reading sometime, rather than just responding with crap.
NOTE: this is the SHOWER, let me repeat, SHOWER installation handbook from your reps that are on all your boards. One more time, this installation manual is for installing SHOWERS, not backsplashes, or whatever else you're claiming w/o any basis. Look at page 2, then look at page 5, then how about page 7, oh, then there it is again on page 9. Oh wait, not done yet, there it is again on page 11. Then there are the pictures on page 12, 14, 15, 17, 19. There's probably a lot more, but I'm already tired of being right.
I will note one more thing... Read page 19. It specifically talks about protecting gypsum board in a wet zone with kerdi. Hmm... that doesn't sound like the bull crap you've been saying on here...