My first interaction with Grendel came from this post: He intentionally changed "transgender" in the title of his post to "transsexual", and his intention was to troll. He pretends to be unbiased, but he introduces a strong anti-feminist, anti-trans, pro-chauvinism tone to everything he posts. Really, I should say "anti-SJW", because that's what he thinks of it. He knows what he's doing. He's trying to infect the hubski zeitgeist with misogyny and transphobia.
Step 2. Post a bunch of subtly anti-SJW stuff, like the example I gave where he substituted an offensive word (transsexual) for a non-offensive one (transgender). Step 3. All the nerds who like the science stuff will be more inclined to trust his opinions on the anti-SJW stuff. Step 4. Reddit.
This is exactly what happened to Reddit. This is the foot-in-the-door technique of all abusers and trolls. Over time, he will escalate the tone of his posts as he gains more support in the community, all while playing the victim. I have seen this happen to more communities than I can count, and I saw it kill Reddit. Read over Grendel's comments. Ask yourself: Is this the example of permissible behavior that you want new hubski users to see and think is normal? Is this something you're willing to let snowball out of the control? Risk of allowing Grendel in our community: Eternal September, breakdown of civility, Reddit-ificiation. Benefit of allowing Grendel in our community: Some good science posts that others would be posting anyway. The rational decision is excommunication.
Step 1. Post a bunch of cool science stuff to get nerds to like you.