Hmm, maybe our opinion on whether it is abuse is coloured by the type of child we have.
Ds1 is Robust. On his first day of school, aged 4.4, he shook me off and ran into the classroom. He did the same at preschool, and I have witnessed a naughty 10 year old boy screaming in ds1's face (believe me I was running to get there!), and he didn't even flinch, wasn't bothered etc.
Sometimes he genuinely only stops buggering about and listens when I shout. And i have tried calm talking, getting down to his level, blinkering his eyes so he can only see me, but I have to SHOUT to bring his attention to what I am saying.
my shouting has NEVER, not ONCE upset him enough to make him cry. And I do get angry. (I stamped my feet in frustration once and he quite justifiably laughed at me)
Ds2 is a different child, and had he been my first, I could see how parents could think shouting is awful and your child may be damaged by it. He is much more sensitive to my moods, and 'the eyebrow' works on him. The query "Do you want to go and sit on the naughty step?" delivered in a quiet but stern voice is enough to make him do as he is told, always.