About: İ̻̦̥ͅ ̻͍͖̒a͔̳̋m̪͒ ̄a n̬e̩͆r̹ͤ̀d̪̹̏̍ l͖͕̺ͦͭo̰̮ͩͨ̚v͇͍̞͒ͭe̺͙̐̉ͯs̺ͤͧ͌͑ ̬̤̹̊̂l̖̳̖̐͛ȇ͉͉͍̇a̘̦͂͒ͭr͕͖̘ͫ̅n̬̟ͮ̓̓i͙͑ͣ̈́ͩn̼͔͋ͨ̚g̩̟͚̒̾ and computers
Almost any OS is just a Unix derivative or at least inspired by it except few OS(s). The Unix ideology is everywhere. Was there any OS during the 1970s with a very different aim and philosophy.
What were the other research institutions around the world doing at that time? Hadn't they made anything like Unix?
There were plenty of other operating systems. What happened is that computers changed. Unix (which itself descended from the earlier operating system Multics) was in the right place at the right time to both drive this change and be driven by it in a hardware-software dialectic. As mainframes yielded to minicomputers and then to microcomputers, operating systems built for those systems, like DEC's VMS or IBM's TPF, largely went the way of the dodo. They're still around for certain uses, but the vast majority of developers will never work with one.
I imagine there was a lot of pressure to have compatibility that led to unification around Unix.
So either you make something derivative or nobody is going to use it.