If I remember right it was partially Glock's fault. Something with the loaded round indicator didn't meet the Mass requirement and Glock said it did. I would also have to assume that the cost of testing would easily be recouped by the flood of sales on XD's alone not too mention the rest of their M1A and 1911 product line.
I guess we can complain all day but the choice is theirs and they have made it. Hopefully Goal can work some magic and fix the insanity in our gun laws!!
The M1A is already sold in MA since there is no list for long guns and it complies with the AWB. Good luck finding large cap mags though.