I actually talked about that with my friend and we came to conclusion that blizzard should just open sometimes tournament realm for people that achieve some X ranking in PvP. Meaning absolutely nothing you do there will come over to your main account, everything would be regularly deleted BUT you will gain access to gear vendors and can compete with other players on the same terms.
And it could be a great spot for community held events.
So long story short, you want to play purely competitive? Earn X ranking and that will get you tournament realm access.
However I wonder if anyone would be playing there...