If you can't get the game to run with good performance and look great while doing so with your rig, then you are doing it wrong.
Get into the config file and make some changes.
On the right blend of settings, this game can look quite gorgeous during high intensity battles (assaulting towers, at night, with multiple platoons against each other, on Ultra settings? mesmerizing with all the tracers and explosions), especially when you consider this is an MMO and has to deal with the computational issues that come with such.
A game that can support thousands of players, with numerous battles alone having hundreds of participants, is not going to look as good as top of the line AAA titles.
Would it have been better if they used DX11 for their new engine? Definitely, but with a F2P MMO that's a bad business decision at this point in time - they'd be swearing off a fair number of potential players. That said, they should eventually craft a DX11/DX9 hybrid engine, it's very much possible and would benefit everyone.
Until then, what they have now actually looks gorgeous imho (on a blend of mostly Ultra settings).