Some roosters can be nice to people and hens their whole lives - these are the ones you happily keep. Other roosters can be nice, but then sometime between 6months and a year suddenly it's like a switch is flipped and they may start attacking people with no or little warning. You never know which type of rooster you may get, although it does seem to be genetic (bad roos often sire bad roos, and the reverse). They are not at all like dogs and cats, and many instinctive human behaviors are interpreted totally differently by roosters than the way we mean them as humans.
My most recent roo was fine until around a year old. Sad for him, still miss him, but his genetics combined with how we kept him was not workable for us. Especially when kids are involved.