Initial enmity generation and player bad habits.

[TouchandFeel]

Yes, its not new and it will always happen, its the regularity of it recently that I find disheartening though. It is so bad that pretty much every other run I do via df and even pf now, I am having to say something like "please don't use regen during a pull" or "I would really appreciate it if you didn't pull the boss", etc.

[Fyce]

"please don't use regen during a pull"

I'm pretty sure you wanted to say "please don't use regen before a pull".
... because regen just at the start of an encounter, after the tank started to generate enmity, is actually one of the best way to heal him during the early enmity generation phase.

[Teryaani]

"I would really appreciate it if you didn't pull the boss", etc.

I hadn't done any duties recently other than ST and I just assumed the RPDS pulling was just a side effect of the troll-fest that is CT/ST. The thought of seeing that in things like primal fights is disheartening.

[Duelle]

I am having to say something like "please don't use regen during a pull"

I'm still coming to terms with why the devs would make overhealing from HoTs generate aggro. Regen (or should I say, Prayer of Mending) prior to pull is a habit healers from WoW developed to cushion damage taken by the tank during the pull while the tank positions the boss and so on. That tactic may not seem valid or useful here with stoneskin and adloquium, but a WAR tank would benefit from having that extra cushion of healing, for example.