Because you have to lead by example. For very new communities, that means one person carrying the new content on their back, until other people decide to chip in.
That you consider it “spam” suggests to me that maybe you weren’t around when the internet was small, and never saw a small message board still in its new/growth phase, and are conflating a single member or mod carrying the content on their back with the karma-farmers that pop up on the better-established forums.