I highly doubt they would lie about something like that... And it's really not all that strange to believe that the amount of people who takes PvP even remotely seriously in this game is an extreme minority, just look at the players around you. Most people don't even have PvP gear, and amongst those who do not many of them take part of any arena or rated battleground, and even amongst those not all that many does it seriously but mostly for points.
Looking at Battlegrounds in general is another great way of seeing it, most people just don't care and even bot for XP/honor not giving a damn about the actual PvP gameplay. Amongst those who don't bot most people just sign up to mess around or have a fun time, not to become better at their class and PvP in general, because most people don't care all that much about it. (Same can be said about LFR.)
The majority of WoW's player-base are extremely casual and barely make it to the end level, even when they do they don't do anything serious and will most likely roll an alt anyways.