Where I grew up, the only difference between a bully and not a bully was who won the fight.
It seems that a lot of the kids now are all ego though. They understand humiliation but not humility eg. "you win some, you lose some.". I learned that in 4th grade when I started wrestling. You give it your best and occasionally still get beat, then go to practice and try again next week.
That held true through the school system too. In middle school you go from being a big 6th grader to a twerpy 7th grader, and in our district, you also had 3 boroughs in the mix. At that point there was all kinds of boundary testing and peck order getting hashed out on a regular basis. Eventually it settles down and everybody moves on.
Then came high school, and I had to switch out of one district and into another. Thats when everybody in the district figures they have to check out the new guy and see what he is made of. They found out. By then though, my perspective was that they were doing just that, testing. So we'd fight, and it never went well for the other guy, and after a while word gets around to not fuck with the new guy.
So was that bullying? I don't think so. It's just basic human behavior. Guys push and shove with their hands, girls do it with their tongues. It's territorial pissing 101.
Then comes the real world. There is always some pushy, blustery asshole who will try to buffalo people into getting his (or her) way. I have never been anywhere that there was not, but that is one of the things that people learn how to handle in grade school that is not on the curriculum.
This next generation of whiny kids are going to be the ones who are running to the HR department or their attorneys office to claim a hostile work environment because they are being bullied "AGAIN!" because they never figured out how to handle it when they were kids.
Dragging some kid who killed himself into it doesn't help. What his room mate did was thoughtless, and how he responded to it was completely irrational, but for christ sake, that is not bullying. If anything, the attempt to make the connection of that to anything else is just a blatant seizure of opportunity to push a pet agenda.