Well, maybe. The "wrong size" problem is only part of the story. Another is that many bras are generally poorly constructed, lose their shape after continued us

Well, maybe. The "wrong size" problem is only part of the story. Another is that many bras are generally poorly constructed, lose their shape after continued use, and sizing is not the only issue (fabric tolerance, flop etc). But more than anything else, the problem is price. A "good" workhorse bra (workwear, not lingerie fantasy stuff) will set you back on average, oh, say about $65 ($100 is not uncommon). You probably need half a dozen. I have no idea what the economics are and why they are so expensive, but I can't imagine what price a "Kinect 3D" custom bra would come in at. And the other aspect of "a good bra is hard to find" is that once you find one, there's a huge lock-in factor. Women will re-order the same model for years. So yeah, while there is certainly a non-zero market for something like this, it's probably not huge. Witness the fact that it is quite easy and even not too pricey to get custom jeans made to measure, and yet the majority of the population doesn't.