Earlier quoted context omitted.
It's too coarse grained and has annoying and inflexible semantics regarding umask and the setgid bit. And you can only have a single group granted read or write access. What about granting an additional group read-only access? For situations where one group has responsibility for maintaining a dataset, but others need access to the data but are not permitted to modify it. You could use the other permissions, but not…
Multiple editors are needed rarely at my workplace, and I haven't had one case which required multiple editors and multiple readers but no global read only access (in > 8 years). If I had such a case, the ACL solution could easily be emulated by putting such a directory below another directory which is accessible only to readers and writers. (Yes, files would need mode 664 and the right group. Not saying it's not a k…
Regarding using a "proper VCS", it depends upon what kind of data you're dealing with. We use git for all our code, but git has zero permissions associated with it other than the execute bit. We use the filesystem for data files; we have many terabytes of uncurated and curated data for integration testing and other purposes. Some people have write access to curate it; some accounts need read access (CI slaves, developers); other accounts are not allowed to read it (some is public, some is under NDA, and other restrictions apply).
I certainly agree that on Windows this can look horrific (and is horrific). However, all I'm suggesting for this situation on Unix is to add a single group access control entry, and optionally file+directory inherited entries to ensure their propagation. You add them once at the root, and then that's it; they are set and done. Since you are using just one group permission, you're not getting a huge explosion of entries, and it will remain clean and understandable. I've seen repeated problems with the basic Unix perms over a five year period here which require repeated action by the admins or guilty parties to fix them up, plus the issue with access via Samba or NFS on client systems accessing the data. That adds up to a maintenance burden which can now be eliminated entirely, making life easier for everyone concerned and the infrastructure is more robust as well. None of the end users even need to be aware of the existence of ACLs; unless they manually screw with the automatically set ACEs, it will just work. As with everything there's a cost/benefit to consider; there is a cost, but ACLs are not universally bad.