Sometimes, a rooster will fixate on a particular person, all "hugging" aside.
And in my experience, petting does not MAKE a rooster become aggressive, but it does let him know which person he considers more on his own level if he does have the makings of a human-aggressive male in him. If a male thinks you are equal with him, if he tends toward human aggression anyway, he will take you on when the hormones kick in, no question. That is why, sometimes, the friendliest cockerels as chicks turn out the be the meanest suckers when they start mating the pullets. If he is "genetically programmed", for lack of a better term, to be easygoing and calm around people, no amount of petting is going to turn him mean.
I don't think you should coddle roosters after they are leaving chickhood, though. I'm a believer in giving them their space, as long as you can catch them to do what needs to be done when you have to, such as toenail trims or fixing injuries, etc. I have several good roosters who wouldn't even nip me, much less flog or rush me. I can do whatever I like to them. They were handled as youngsters, but not babied. You just need to be able to handle them when you have to.