But dps and healers right now absolutelty, mathematically, factually and objectively do not have the same value, AT ALL. This is not an opinion by any stretch of the imagination. I don't think Blizzard believes healers have the same value as DPS either. I'm sure they know healers have more value and I'm also sure that's what they want. The model of 2dps+heals for 3v3 looks good, doesn't mean it's balanced tho.
In PvP the game can be balanced, because it's only classes against classes. In PvE it's harder to balance because the encounters are different from one fight to another so a class that has good AoE like ele shaman for example suddenly has more value just because of what content they find themselves in. In pvp there's no content changing, it's always the same, you only fight the existing classes. So it's very possible to reach a good balance there. Which is a good thing because balance in pvp is far more important than in PvE.
I agree that balance is not the only reason why pvp sucks, but it's one of them.