Some of us can! I certainly enjoy doing it, and according to "man 5 acl" what you assert is completely false. Unless you have a particular commit or document from kernel.org you had in mind?
See 6.2.1 of RFC8881, where NFSv4 ACLs are described. They are quite similar to Windows ACLs.
Here is kernel dev telling they are against adding NFSv4 ACL implementation. The relevant RichAcls patch never got merged: https://lkml.org/lkml/2016/3/15/52