HM skills, Soulstones, etc items. Right now the pouches from doing the 4 dailies give a decent amount of SS, so that's awesome. But it still feels like NCsoft is shoving PvP down my throat with every addition they make. "Here's a practice arena!" "Here's a new tower that is nothing but PvP!" "Here's a new battleground....that's PvP!"
On subject to the quote though, yeah, you want HM skills to kill better and faster in PvE. Best way to get them is PvP. Upgrading my Siren weapon required me to PvP in Misty to grind insigs. Some form of PvP is required to progress in PvE.