What are the most common reasons people don't dps?

[Sida]

I used to be a healer in WoW back years and years ago and when I came to this game I picked WHM because I knew healer is what I want to be. During my leveling and way into 50 I didn't DPS. Mostly it was because I had been strictly taught in that previous mmo that healer should not dps, or at least use mana for it (auto attack with wand for the win \o/ ) So as for the question, the reason was that I had learned different healer culture, one where healers were loked badly if they "waste their mana" to admittedly lackluster damage spells in that game.

I was later lured to try the damage part by some friends and found out in this game the damage spells are viable enough compared to the resources they need, and that I can still fulfill the healing needs with the resources I have and have been happily boom ever since. But originally it wasn't even fearing failing, it was just assumption I should "stay in my healing role" learned elsewhere.