That's a great question. Some might say it's because of the network - that makes microservices messy and so on. But I dont think so, from what I remember plan9

That's a great question. Some might say it's because of the network - that makes microservices messy and so on. But I dont think so, from what I remember plan9 (the os, successor of unix), Rob Pike wanted to make it so that there is no difference between an object being on the network or outside the network. In unix philosophy, things have the same interface, it's easy to communicate. For microservices it would be REST api which is unique to network things. I honestly see a direct link between these ideas. Unix here is projecting a much nicer, simpler image but nonetheless they seem to overlap a lot. The result in both cases seems to be a hard to debug network of small utilities working together. The saving grace for unix is that you are mostly using stable tools (like ls, cat), everything is on your system so - you don't get to experience the pain of debugging 5 different half-working tools.