It seems they are already spending a ton of time developing arenas... If they put in a bit more effort they could be making so much more money from the RMAH and tournaments
I found this link on reddit and the guy seems to make a lot of level-headed arguments on why PvP should be competitive
Here's a much more rage-filled entry lol. I don't agree with everything he says but its funny how vehemently he attacks Blizzard.