To be fair, equalization can be used to correct speaker efficiency differences (smooth roll off). A crossover does exactly that, to make multiple drivers blend, and it's been done by several speaker manufacturers (from the dreaded Bose, to the not-so-dreaded McIntosh, to the downright liked Martin Logan).
One problem with relying on YAMO or Audessy is that they are, what, 9 frequencies with some sort of logarithmic roll-off? The speaker may not be non-flat in that way.
Said another way, though an equalizer tries to correct to flat, that might not be possible without a custom built (for those drivers) equalizer, and that still won't help if there's resonance (which occurs at a different frequency than the sound). And none of that even begins to touch on-axis-vs-off-axis performance.
There are some respected speaker makers who believe that custom equalization is a good way to correct for some types of speaker behavior (Roger Russell was a proponent of using sealed enclosure bass and and equalizer on (for example) the XR-series), but it will not fix an erratic driver (one with dips and spikes all over), or issues like resonance.