There's a lot of theory here that doesn't hold up to practice.
See the part about reserving judgement for months to see how things actually played out. This change clearly did NOT force 4xxxCM builds, nor did it take away the value of rolling a dedicated healer.
-Groups are still able to complete nightmare heroics.
-PvP groups without a healer generally get stuffed by the team with the healer
Those are both facts that are objectively true and backed up by metrics.
Let's stop with the cope arguments please and focus on fact. This change went through the proper process of feeling out the change instead of reacting emotionally. I hear what you are saying on paper, but it doesn't hold up in practice.
Asking for a healer to be balanced around guaranteed survival in a 2v1 is ludicrous, and would break balance of very many combat mechanics in both PvP and PvE.