While it's true that our ears will filter out the "room response", our ears can't filter out the direct sound and all other sources of sound (early reflections) that happen inside the Haas window.
There seems to be two solutions to this problem...force the early reflections to be lower in amplitude, but let them arrive right away and decay naturally....or force an anechoic response for the Haas window and then set the natural decay off the first late arriving reflection.
Both solutions, however, don't involve the use of EQ except for the tailoring of the direct sound. The goal of EQ'ing the direct sound is to maintain the timbre balance of the sound that is projected into the room. For speakers without constant coverage, the sound will need to be tweaked a bit to compromise the direct sound with the overall power response.
Any frequency response aberration is going to cause a corresponding shift in the phase response. If it is minimum phase, then a filter of matching Q and gain will fix both the amplitude and phase response. The fixed bands of a graphic equalizer don't allow for this level of fine-tuning.
I think the main reason that graphic equalizers don't exist anymore is because the modern mass markets just want plug and play....the graphic EQ is more of a tweaker type thing that lends itself to constant adjustment. Also, it seems like the majority of people just end up with smiley face EQ curves, which can be just as easily accomplished with two tone controls. The typical speakers these days seem to have better tonal balance as well.
Of course it sucks for someone that still wants one anyway, but I don't see any reason why it couldn't be done with a more discrete route. I would highly recommend looking at the Ashly units:http://www.ashly.com/gqxseriesgraphic.html