We certainly design Crossplane with the intent that end-users will interact with a "Composite Resource" API, not use MRs directly. Little bit like end-users using a Terraform module curated by their platform team rather than writing resources directly.
From the post it seems like interacting with Crossplane Managed Resources is done via a simplified "userspace" CRD/controller and not directly. Is direct interaction a Crossplane anti-pattern? It seems like both approaches have their own advantages.