> When these machines were announced and their functional specifications became known, quite a few among us must have become quite miserable; at least I was. It was only reasonable to expect that such machines would flood the computing community, and it was therefore all the more important that their design should be as sound as possible. But the design embodied such serious flaws that I felt that with a single stroke the progress of computing science had been retarded by at least ten years: it was then that I had the blackest week in the whole of my professional life. Perhaps the most saddening thing now is that, even after all those years of frustrating experience, still so many people honestly believe that some law of nature tells us that machines have to be that way. They silence their doubts by observing how many of these machines have been sold, and derive from that observation the false sense of security that, after all, the design cannot have been that bad. But upon closer inspection, that line of defense has the same convincing strength as the argument that cigarette smoking must be healthy because so many people do it.
OS/360 was a victim of over-ambition. Originally, it was to run on all models of System/360 (maybe not the Model 20, which implemented only a subset of the ISA), and it was complex enough that there were challenges in building it. IBM ended up spinning off the smaller models to IBM Germany, DOS/360 came from there, and subsetting OS/360 into 3 levels, so they could get something out the door only a bit late. OS/360 by some measures is one of the most successful operating systems ever: IBM's current z/OS is a remote descendent of it. Yes, it is pretty horrible to use (three letters: JCL), but it certainly was successful.
“The Mythical Man-Month” is not about OS/360 as such, but about project planning and specifically what was learned about project management during the development.
Sadly we went from over-ambition to mostly UNIX clones in modern OSes, which triggered Rob Pike's famous rant on systems programming, or his remarks on Slashdot interview.
> When these machines were announced and their functional specifications became known, quite a few among us must have become quite miserable; at least I was. It was only reasonable to expect that such machines would flood the computing community, and it was therefore all the more important that their design should be as sound as possible. But the design embodied such serious flaws that I felt that with a single stroke the progress of computing science had been retarded by at least ten years: it was then that I had the blackest week in the whole of my professional life. Perhaps the most saddening thing now is that, even after all those years of frustrating experience, still so many people honestly believe that some law of nature tells us that machines have to be that way. They silence their doubts by observing how many of these machines have been sold, and derive from that observation the false sense of security that, after all, the design cannot have been that bad. But upon closer inspection, that line of defense has the same convincing strength as the argument that cigarette smoking must be healthy because so many people do it.