Correct, partially due to not being able to efficiently do the rendering on that platform. It would have to be something like the path that they have for 360 for DX9. Indeed go google some videos of console footage of BF3; it looks fine compared to other console games, but it's not even in the same league as the PC visuals. Not everyone has the resources to write basically 4 renderers (DX11/DX10/360/PS3!), but I think it is one of the very few unique examples where DX11 is actually put to good use. Crysis 2 DX11 is decent, but it definitely still feels tacked-on, whereas BF3 feels designed for DX11 then cleverly ported/scaled-back on other platforms.PC version does not support DX9, if I'm not mistaken.
These days whether a title uses DX9/10/11 doesn't necessarily tell you much about it's rendering sophistication, except perhaps if it uses DX9 it can't really be super-modern (use compute and other capabilities).