I fully get your point, but the fact still remains that most people don't have that anechoic data and likely can't get it, nor is it available for every speaker, nor can everyone accommodate a way to measure it. In these cases, as least we can measure the speaker in the room and see what it looks like, and see what's happening with what we will actually be attempting to correct. Then we can use Dirac Live (or whatever we choose) and possibly make it sound better... and that is the ultimate goal.
While having the anechoic data may help us get closer to accurate, it is not going to make us hear the difference between corrected (whether it's accurate or not) and uncorrected response any better, it's just data. If it's my mind playing tricks on me that Dirac or Accurate/Audiolense correction sounds better than uncorrected, I'm gonna let my mind play tricks on me every time I listen to music, because to my mind it sounds significantly better corrected.
If we do a comparison, and no one knows what preset is corrected and which one is not, and we play both, then the very least we can determine is if I minds are actually playing tricks on us.
The target curve most users are using is that of Harman... which is anything but subjective.
Whether controlled or uncontrolled, results are going to be amusingly different. When we did one of our speaker evaluations, not everyone preferred the Dirac correction to the uncorrected on every single speaker.
Either way... I don't think anyone is gonna go wrong using Dirac or Accurate/Audiolense, especially up to 500Hz. As Toole points out, his major concern is what these systems do above 500Hz, not below. I say compare what you have to work with and go with what you like. And there are plenty of guys out there that don't like the corrected versions, so for those guys, correcting it didn't make their minds cause them to think it was automatically better.