You're wrong. First of all technologies do not change that often. DX releases happen about once a year with the exception of XP induced 4 year stall period. AH could be the autobahn where top speeds are unlimited (i.e. using DX11 and supporting lower levels also like larger game titles do) right now players are limited to 10 year old tech (DX9 and even that is not fully implemented) so their fancy GPUs sit on idle most of the time. It's comparable to having a Ferrari and not being able to speed more than 45mph. Those who do have ferraris might want to do 120mph or more but are handicapped by people who have Ford Pintos. The lawmaker (HTC) can not build enough lanes on the highway due to cost so that the Pinto drivers could chug along slowly while letting the Ferraris run on the speed lane.
That's why HTC has to balance the speedlimit on the one line between not losing the Pinto drivers at the expense of all the Ferrari people clogging up their engines at idle rpm commutes
AH has been CPU intensive mostly not because it has to do simulation calculations but because it has not used CPU offloading graphics technologies provided by DX.
That is not accurate at all. Graphics have been offloaded to the GPU for some time (it has been up to DX to take care of it via the fixed pipeline). The only reason some boneheads think differently is due to how long it took to get around the CPU portion, each frame. The time spent in the CPU side artificially lowered the busy time for the GPU as GPU's got faster and faster. This caused the various end user tools to report loads inaccurately.
We have been itching to offload more to the GPU, but had to wait until AMD and NVidia finally supported a shader model equally. SM3.0 finally bridged the gap between the two companies. Then we had to wait until the lion share of the market reached 3.0.
What DX level we use is based on the lion share of the marketplace. Until DX9 is a minor player, we will continue to use it. It makes no sense to do otherwise. There is very little to be gained for us to migrate passed DX9 as we have found we can graphically do everything with DX9 that can be done with DX11. Those who think moving to DX11 will magically make graphics better are clueless and have simply bought into all the marketing.
No doubt someone will bring in the Steam numbers, which are quite bogus for our player base.