I have a couple of theories on that too. I think you are right a lot of the problems are unintended males in a purchase. And I do agree that raising them with a flock helps, whether that is with a broody hen or keeping them with the flock even if housed separately for a while. Just don’t wait until they hit puberty to integrate them. If you have room, you don’t have to wait.
My first theory carries over to a lot of things. I think most of the integration issues, rooster issues, pecking order issues, and broody hen issues we read about on here happen when space is tight. If chickens have space they will solve most of their behavioral problems. Occasionally you might get an Attila the Hun or maybe Lilly the Hun, chickens of ether sex that are just brutal, but in most cases they will work things out if they have room.
My other theory will upset some people, but I think a lot of the problems aren’t problems at all, at least for the chickens. I think a lot of people new to chickens don’t understand what normal behavior is. If they see one chicken pecking another chicken it is time to call out the National Guard to restore order. Put that brute in time out to teach it good manners. Don’t let them see a rooster mating a hen, that has to be pure torture for that poor hen. It’s obvious she did not want him mate to so it has to be horrible. People not raised around flock or herd animals don’t understand how social animals interact. There is a reason a rooster grabs the back of a hen’s head when they mate and it’s not that he is being an awful brute. It’s the signal for her to raise her tail out of the way so he can hit the target. They could not mate if he did not grab the back of her head. Once you explain the why to most people they get it, but not being around animals like this before they just don’t know what to expect. From her posts above, LitttleRedCoop is someone who gets it with a bit of an explanation.
I guess I have a third theory. Most of the problems reported, usually cockerels but often pullet flocks too, are when they are teenagers. Hasn’t anyone ever raised teenagers before? When those hormones hit, boys or girls, and they don’t yet have the maturity to handle it, things can get really exciting. Most teenage kids grow up to become responsible mature adults. Most teenage pullets and cockerels grow up to become mature flock members that understand their role in chicken society. That transition from childhood to mature responsible adult can get pretty hectic.
Anyway, off my soap box. Now back to regular programming.