Over-healing should not generate extra threat

[Zplinter]

As a white mage, I should be able to freely use regen without complicating pulls for a tank. It really is that simple.

This is a gameplay/mechanic issue. It's not a player issue. We have regen for a reason. And that reason is to use it. There is adaptation. Then there is just poor game design. This issue fits in the latter.

Herein is the problem. You expect to freely use any skill you want when you want how you want. All about you. Your derision of other players telling you that they disagree is telling. So it is fact a player (you in this case) issue.
This is a game where the devs have set up the mechanics in such a way that skill use is situational, This is NOT FF XI, this NOT WoW, etc, this is FF XIV ARR. There is a clear vocal majority on the forums that disagree with your premise, as do Devs it seems.
We as players that heal have exactly THREE options: We adapt to the mechanics of the game. We decide we do not like the mechanics and leave and take our money with us. We continue to play they way we want to and accept the outcome.