Comment I briefly worked with one of these (Score 4, Informative) 62
I worked for a while in a shop that did server side Unix systems, and they had a ton of desktop computers for compatibility testing. In addition to the usual suspects, I remember testing on a Dec Rainbow, a Sun 386i, a Sirius/Victor 9000 (nice for an 8088 system), an HP/Apollo, a Lisa (slooooow), a Texas Instruments PC, and this one.
While there wasn't anything actually wrong with it, there wasn't anything particularly compelling about it, either. While it was nice to have a "pure" Unix (as opposed to Xenix, or rebranded versions like Esix), it didn't warrant the jaw-dropping cost. Sure, it was great hardware, and AT&T had the chops to fight IBM on the corporate desktop, but outside of the Fortune 500, most companies were buying clones rather than true IBM for a fraction of the price. The price of this was eye watering to begin with, and while it had great development tools, it had very little commercial software, and what it did have was also overpriced.
You could buy something like three actual IBM PCs with Lotus 1-2-3 for the cost of a single one of these. And when you factored in clones, it was closer to eight clones for one AT&T box.
The business case simply didn't make sense for the majority of the market.