Admitted by BW that 50% of the population plays PvP regularly. So yeah think they do need to put some money there.
Ya, and again BW misses the point. The reason so many people do PVP is because there's literally nothing else to do. It's PVP, grind an alt, or do your once/bi weekly raid. So of course people will opt to do PVP for a while, especially considering how much of a grind it is at 50 to get any gear, so those who want to hope to be competitive will have to grind for a full BM/WH set to stand a chance in PVP.
I'm betting the people aren't as interested in PVP as BW thinks, and probably a good chunk of the ones who left weren't the PVP crowd either.