Winter Blast is valuable for its ability to both heal and do damage. I get why that might be considered too powerful, but I'd much rather keep both effects if possible.
Healing is first priority - I could switch to Polar Wind for nothing but healing, but I'd like to do some damage as well, given tanks' have lower ability to do damage to begin with in solo content - but retaining some damage, even if it's significantly lower, would be better than limiting to one or the other, imo.
To reiterate, Winter Blast should keep the same healing effect it had before, and still deal damage, but the damage dealt should be much lower.
As a tank, particularly in solo content, it's hard to "back off" from a fight enough to trigger the new effect's heal when enemies are focused on you, after all.
Please don't use PVP as a measuring stick for everything, it sours things for PVE players, especially solo PVE players.