Basic learning theory says that if you are using punishment to stop behavior it must be adequately aversive to the animal that it avoids the action in the future. That says that if it is not some degree of painful or frightening or otherwise distressing - ie: unpleasant - for the dog, then it will not work. The more reinforcing the behavior you are trying to stop, the stronger the punishment must be to stop it. All of this varies based on individual dogs. I have one dog I could whack over the head with a 2X4 and he'd just think it was a game, and another if I look at slightly sideways and mildly say 'no' will melt into a puddle of sorry.
And ALL of that out of the way, alphas don't exist in dog packs and in wolf packs 'alpha' is actually 'parent' (natural packs are an adult and their various age offspring and the man who put out alpha theory based on the unnatural behavior of captive wolves RETRACTED IT) so none of that has a thing to do with anything. And even if it did, I'm not a dog and my dogs are well aware I'm not a dog. I don't need to discipline them like a wolf or other dog would. I have hands, treats, access to anything they get comes from me, and a higher order brain with which to problem solve.
And yes, I absolutely tend to think that anyone relying on positive punishment as anything approaching a regular part of MOST training is someone who simply lacks the skill or knowledge to adequately problem solve. Not always, not all situations, but far and away most. Doesn't mean I think they're abusive or the dog's suffering, but my opinion of their training skill goes WAY down when I hear 'it doesn't hurt them/it's the only way you get respect/it's necessary' and they're talking about pet or sports stuff (or really probably 98% of skills dogs need)? I absolutely assume they're a really terrible trainer.
Not abusive. Just not any good at training dogs.