Well, one problem is that for the last 3 years about 99% of the audiophile "press" has been consistently singing the praises of MQA, parroting Bob Stuart's words and press releases as if they were gospel truth. In fact most of what has come out of MQA has been technical assertions, many of which are demonstrably false, as Archimago points out in his article. It is worth noting that in every instance of which I am aware, when called out for one of their "untruths", MQA either admits they fudged the truth, or else responds by discussing something else about MQA, a classic avoidance technique used when there is something to hide. So this is certainly a reason for some of the anger, because silly us, the audiophile consumers, the people who buy or read the audiophile press, apparently don't count.
As far as the angst, Al M. mentioned the reason for that earlier in the thread, and it is something many others in the hardware industry (most notably and frequently the late Charles Hansen of Ayre) have expressed concern about. And it is a reason for concern; overtly lossy and proprietary digital files becoming the only way to buy or listen to better-than-CD quality digital music.