Righteous Fire and Vitality

Hello there,
I am currently building my first RF Marauder since 3.16 or so. And I have a question, one of you could explain help me with

While I was checking for skills to use, all Builts that I have found so far always used a lot of Lifetap Support, but no one uses a Vitality Aura.
What is the reason? Yes, Lifetap would grant me additional Damage on my RF, but Vitality would negate the liefloss nearly completely

RF builds get high fire resist and enough life regen through gear and passives that Vitality generally isn't needed beyond low-mid levels.