It's not forbidden. It's just rarely considered worth the space. I hate to say "lurk more", but you are new here, and you don't yet understand the complexities.
Whatever the reasons for not following standards, no matter what company is doing it, I think they should be weighed against the advantages _to the computing community as a whole_ of following standards. Each user might ask themselves, "Is it more worth it for me to learn some nonstandard stuff that will only apply to one company's products, or to learn some standard stuff that applies to many companies' products."
I see clear advantages to everyone who has ever learned UNIX (and everyone who learns it going forward) of UNIX-like systems having a standard set of UNIX utilities and keeping things in their expected locations. Namely, there's less to learn and potentially wider applicability across a range of products.
