I have to agree, in my experience, uncastrated male stock (bulls, rams, stallions, Roos) that are “very” comfortable with human handlers tend to go from “my sweet baby boy” to potentially dangerous grown adults with much more regularity than stock that is not raised as a pet. I believe that it is just “the nature of the beast” no pun intended. Most intact male animals want to obtain the highest position (in their animal minds) in the social hierarchy possible. When we do inject our human selves into their world their is a greater chance that they will view us as one of them, or vice versa, and the time will come when their instincts will compel them to test where they stand compared to us. And most of the time they will generalize that because one human has related to them on a pet level, all humans should be seen in a similar fashion. Does that mean every little girl who brings up a foal as a best friend will end up with a dangerous stallion in 1-2 years? No, but the likelihood is greater,. And that stallion is also more likely to see its trainer and future owners in the same light. And I don’t think it’s always possible to just “raise them with love and respect” and assume the animal will fall in line. It’s just the way nature designed most animals and when they experience that surge of testosterone they are behaving as nature designed, compete with most anything to ensure only the very strongest are able to contribute to the gene pool. It’s almost intrinsic to all domestic animals to see humans as “a species to be respected” until we the humans decide to blur that line and become something else to the animal. Does that mean that I never raise a rooster as “too much” of a pet? Not at all. I blur those lines all the time. I just try to keep this in mind and not become too surprised when my “favorite roo” decides to challenge me.
Well said, i agree completely!
and with my chickens I've seen firsthand how the roos that i handled the most as babies grow up to be the meanest. I think they do see you as part of the flock if they are over handled and so they want to make you submit to the pecking order with them as the head roo.
To the op:
I have had 5 brahma bantams that i over handled, they are all a year old this march, 2 i sent to freezer camp months ago because they were so aggressive and just sold one today who is not aggressive at all, even though he was raised in the same group of brahmas that i cuddled and spoiled... sold another before who was mild too. and there's 1 more who is mildly aggressive but when you threaten him with the "pinchers" i use to collect eggs, he remembers he is not the boss and ignores us.
So don't play with your baby roos so when they grow up they won't want to keep you in your pecking order place!
I raised a delaware bantam in the same group as those brahmas and some cochins, all together and all cuddled and handled alot when they were young, for about 2 months ti they moved outside, the delaware bantam grew up to be such a sweet boy, i sold him to a family who has young 5 year old or so grandaughter, she will go up and grab him and cuddle him and he just loves it!
The cochins all grew up non aggressive but not sweet either, well balanced roos actually.
My buff orp is a very gentle roo, my easter egger is aggresive and has to be held at bay with the pinchers ,
my "ameracauna" is gentle,
My silkies are well balanced,
My favorelles are evil to each other amd destined to be butchered, but very non aggressive with humans.
Like everyone has said, it really just depends on each birds personality.
I've become rather scarred after all the information I was indundated with when first delving into poultry.....therefore, I'm skeptical of everything. Made some serious mistakes in the beginning. 
