Well, I'm an animal control officer, so I go by what the law determines as abuse (neglect). A cockatiel living in a home has minimal predators and (should be) protected by the owner. I just don't see cruelty here. If you think this is maiming, you've never seen an animal be actually attacked/ maimed by someone.
Does it suck? Yes. Would i ever do this to my bird? If course not. Is it cruelty? not in my opinion. We can agree to disagree
I think we can all agree that the law covers the absolute bare minimum. Food and water? Not gonna freeze or bake? Not bleeding? Good enough. And I get it. A line has to be drawn somewhere and there are undoubtedly worse things to prosecute.
However, something doesn't have to be illegal to be cruel.
Verbal and emotional abuse don't leave physical scars on children, but they're undeniably abusive and can do severe, long-term damage. I don't know if animals can be said to suffer from "verbal" abuse, as I can insult my pets all day long and they never take it to heart, no matter how scathing the criticism. Emotional abuse though? Fear and confusion and stress? They can certainly experience that.
There are scenarios where cutting a child's hair becomes an act of abuse. Is it enough to get a child removed from the home? Not that I've ever heard of*. But that doesn't make it harmless. Certainly we can agree that a bird's feathers, which are vital to balance and locomotion, and capable of pain and bleeding, are at least as important to their well-being as a head of hair is to a human?
*I DO, however, know of a situation where it cost someone their job, and rightly so.