"Almost immediately, they found that they could debunk the time-worn idea that anonymity leads to abuse. Although anonymous comments are "six times more likely to be an attack,"
Hmm, that actually DOES seem to support the idea the anonymity fosters abuse...
I think the net of it is: anonymity encourages some people to be abusive, but enough people are abusive under their real names that you can't say anonymity is the primary factor behind abuse.
Whether curbing anonymity is a necessary component of fighting abuse and/or worth it becomes a further question.
Out of the total corpus of people, there are some who would be abusive if anonymous, however they have enough 'social awareness' to not behave that way when real names are used.
However, there are another subset of this group who lacks the social awareness to curb their abusive behavior even though they are using their real names.
By enforcing a "no anonymity" policy, you filter out the first group effectively but wind up increasing the percentage make-up that the second group has in the overall community.
The study doesn't even address the question of how much real names help. No one uses their real name on Wikipedia. It is just comparing edits from logged in users with edits from people who aren't logged in (sometimes called "IPs" since their IP address is recorded). Also, some abuse from logged in users comes from sock puppet accounts.
It has died down a bit in recent years, but the idea that anonymity causes abuse is widely circulated in gaming circles because of this popular Penny Arcade comic: https://www.penny-arcade.com/comic/2004/03/19
A question that always comes to my mind is that are we better off if we don't allow or cannot be abusive/intolerant/nsfw. If people do it when they are anonymous, it's still inside them, even if they can't say things. Maybe it's better for the society if there are places where they can satisfy their urges.
Hmm, that actually DOES seem to support the idea the anonymity fosters abuse...