This isn’t a bug. We include the value of all healing effects, including effects like pain suppression, leniency, damage reduction from versatility, etc. That causes the value of crit/haste to go down a bit since they don’t scale with those stats and the value of versatility to go up. We are the only people using simulation to value gear for healers as well, which often leads to different suggestions than other sources of information because we are able to use a more complete model of the game.
All the healers I’ve talked to who use the advice from our site have successful results in-game. I also main a priest and use the suggestions from the site and do extremely well.
Think of our advice as another viable way to play the game that has solid data to back it up. There is more than one way to play a healer and be good!