Raiders comprise the smallest, by far, group in our game. PvMP players are far larger and even they are small. in fact together the two groups wouldn't comprise 10% of the total player base and never have (this is important. it's not a new thing, it's a long standing historical fact).[Thanks to Dan for the tip!]
Forum posters comprise a slightly larger group than the combined group of PvMP and Raiders. However, Raiders and PvMP players make up the overwhelming majority of forum posters (More than half. Though raiders are the smaller group of the two (PvMP/Raiders)). So you have a tiny group, inside a small group that is grossly disproportionately represented on the forums.