The KC-10, which you were referring to, had one (long) shift of very dedicated engineers, and the lead engineer came from ITEL which made IBM compatible mainframes. He had (an easy to understand) fundamental misunderstanding about PDP-10 architecture which impacted functionality, not performance, as the KC-10 was going to be the fastest machine DEC ever made. He caught mono, and found his misunderstanding while stuck at home with the hardware manuals.
The thing that actually killed the KC-10 (and the KS-10 desktop successor) was the VAX, which Gordon Bell went all in on.
The thing that actually killed the KC-10 (and the KS-10 desktop successor) was the VAX, which Gordon Bell went all in on.