Who is stating that Spriests do not have it bad? They do. What is being argued is it is not beneficial to drop warlock to spriest level. Spriest needs to be brought into the fold. Ranging while moving is the way the game should go, not back into the days where you had to stand still to dps. That boat has passed, encounters require more and more movement each tier.
Making warlocks stand still to do dps isn't going to help Spriest at all. What it will do is kill the fun and gameplay changes that have been made through the tiers and MoP.