I think Zak hit it on the head.
People know a direct thread will at least mount consistently. Granted there are other variables in making an accurate can, but that can be crossed off the list.
Unfortunately, there have been a couple of QD mounts that aren't so stellar, and the can will not mount repeatably and/or securely. I've slowed down a video of a 762-SDN on a bump fired 5.45 SBR that had deflection bad enough during bump fire that the human eye can see it.
When one of the big players botches it so bad, everyone else suffers. When you are stacking up to AAC, you have a lot to overcome to convince the general public that your system will solve the issues they have seen. It an be done, but it will take solid proof and more than one source to do it.
I bought a TOMB style can, won't say who from. Speaking from personal experience, I knew that I didn't have to put any more work into researching a QD setup to determine how solid the mount was to know it would be repeatable and acceptable. From my standpoint as a consumer: until my preconceived notions of how a QD can locks up, it is easier for me to do a direct thread or a TOMB style can than it is to research a specific QD mount. I think that until the stigma of QD mounts is cleared, SIGNIFICANT marketing power would have to be poured into a QD product for me to notice it, believe in it, and spend money on it instead of going with a known good approach for accuracy since both are offered readily.
I have stamps in on a couple of QD type products, but they aren't for my accuracy rigs. They are for other purposes.
Hope this doesn't come across as confrontational. Just telling you what a 'slightly above average' researcher thinks when looking for a new can. Maybe it can help you with your marketing strategy, or other areas to help cure the stigma of the QD can.