[phailhaus]

Yes, it's due to structure. If you view social media sites as games, you can see why certain behaviors emerge from each one depending on the platform's rules. If you want to discourage abuse, you need to develop mechanisms to disincentivize it.

For example: the way Twitter works, an individual's reach is proportional to the number of their followers. This means that individuals can influence thousands of people with a single tweet. That's a lot of power, but that's also a lot of attention focused on one person. So it ends up cutting both ways: we see prolific tweeters able to spread their ideas really easily, but we also see witch hunts where huge groups all gang up on one person with devastating effect.

YouTube sees this for the same reasons, but the scale is smaller because creating videos and response videos take significantly more effort. LinkedIn could, but it doesn't because it's really a website for making yourself appear attractive to employers.