I'm also increasingly sick of the Linux eco-sphere these days. I think there is something to be said in favor of Linux ditching POSIX and other standards and that this inclination has definitely had some positives and pushed us forward further than we may have gone otherwise in some areas.

But I don't think a total lack of a standard was what should have replaced Unix standardization efforts.

I think my real issue with Linux is that it is increasingly complicated (both the kernel and most distributions). It doesn't feel as "open source" as some of the not even quite open source Unix's, because you need to be a domain expert in a particular area for you to be able to modify it correctly. When you've got a team of people responsible for the whole OS as a single package, there is some incentive to keep your area maintainable. You never know who is going to be switching teams or knocking on your door. With Linux the incentive structure is to make a name for yourself as "the <particular subsystem or utility program> guy", which opens up a lot of potential for feature creep and overengineering.