While I agree that people tend to get panicky and the forums tend to devolve into an echo chamber ("I'm outraged!" "I'm outraged too!" "Look at how many people are outraged!"), I think it's important to separate "OMG, why did you nerf me" complaints from "Your statements seem to have a logical hole in the middle of them."

Balancing PvE healers around offensive dispels (especially when they lack the proper hit rating and the cost is going up), for instance, makes little logical sense in a game where DPS (and even prot warriors) are able to assume the same role. DPS won't have to switch targets to do the dispel and two seconds of lost or diminished DPS will (in almost all cases) be less of a burden than two seconds of lost healing. While it may be true that defensive magic dispelling will be the only required function, the blues stated there will still be curses, poisons and diseases, meaning that guilds (especially those who are on the cusp of downing a boss) will be penalized for taking a shaman or priest.

Also, there's the problem of trusting Blizz's ability to implement their vision. Remember when GC said they wanted healing to be less spammy? In some fights in ICC, it definitely feels more deliberate... And then there's Bonestorm. And Koralon and Toravon (the VoA bosses being all the raiding some people do). I would prefer if the start of Cataclysm wasn't like the start of Wrath where resto shaman were mediocre tank healers if they stacked enough crit in Naxx, then not-particularly-effective spot healers in Ulduar and finally Chain Healing turrets in ToC and ICC when haste stacking started to work. That's three different mechanics for the same class/spec over the course of one expansion. As a result, it's difficult for me to take on faith that Blizz knows what it's doing, has a vision and everything will turn out roses.

I'd rather comment now, explain my concerns and have things shipped in perfect shape than sit back and assume that everything will work out fine.