People who denounce sexism because they've got a moral framework or intuition that tells them sexism is bad are principled actors. People who denounce sexism because they're trying to get likes on social media, because it grants them social approval, or because they've made a job out of it are acting out of self-interest. Not everyone who is in the second group knows what their motivations are: people usually come up with seemingly altruistic reasons for self-interested behaviour, and genuinely believe those reasons, even though they wouldn't behave that way if they weren't getting anything out of it.

As per the article, "punishment should be proportional to the offence", and punishments should ensure the offender will "constructively come to understand, repent, and make amends for an infraction". The first group can be relied upon to see transgressions in light of their broader moral principles. They won't always seek punishments that are proportional and restorative, because those are moral principles in themselves, but they'll at least be trying to do what they believe is a good thing.

The second group is scary because they just don't stop. They'll keep doing things in order to get the reward of social approval or social media, for as long as that reward lasts. Even worse, because they don't have good introspection about the underlying rewards that incentivise them, they'll reward each other for escalating. They'll tear people's lives apart without a shred of guilt, because they're getting something out of it, which is why they're seen as predators.