And the feeling of mis-features being the other company's fault was mutual. Microsoft people viewed the introduction of more UNIX-like features into MS-DOS/PC-DOS 2 as happening despite the strenuous objections of IBM, for example.

People do this. I've seen this happen in places that have nothing to do with IBM or Microsoft. Problems and misfeatures are all the fault of that group of incompetent outsiders in that company over there that we have a business deal with. It is rarely actually true, in my experience.