I hope you’ll all forgive the pedantry, but it seems clearly laying out the argument might be the best way to avoid a flame war that isn’t making anyone look good, or encouraging rationality particularly. If this post is downvoted, I'd suggest we leave the topic.

NB: I don’t know enough of the history to judge who is more/less right/wrong between Alicorn and SilasBarta, and even if I could, probably wouldn’t say. I solely intend to attempt to clarify what SilasBarta meant.

Summary of what I take to be SilasBarta's argument:

• SilasBarta replying to Alicorn causes Alicorn psychological damage because Alicorn dislikes SilasBarta.
• If Alicorn did not dislike SilasBarta, Alicorn would not incur psychological damage when SilasBarta replied to her.
• There are advantages to Alicorn of being able to freely discuss with SilasBarta.
• If Alicorn did not dislike SilasBarta, these advantages would outweigh the costs (e.g. time taken reading his replies).
• Alicorn doesn’t get any benefit from disliking SilasBarta.
• Hence it would be beneficial for Alicorn to cease disliking SilasBarta.
• Alicorn is (as reasonable an approximation as a human fairly expect to be) rational.
• Hence if something would be beneficial for Alicorn to do, she would do it.
• Hence if Alicorn could stop disliking SilasBarta, she would do so/would have done so.
• Alicorn has not ceased disliking SilasBarta, and does not appear to be doing so.
• 11) Hence Alicorn does not have a general method for stopping disliking people.

Possible counter-arguments:

• Alicorn’s method relies on focusing on positive aspects; SilasBarta has no/too few positive aspects for this to work.
• SilasBarta’s comments have no interest to Alicorn.
• Alicorn has better things to be doing with her time than building a good relationship with SilasBarta.
• Alicorn thinks there are lower-hanging fruit than SilasBarta.
• To start liking SilasBarta would signal that her threats weren’t credible.
• Alicorn’s method has to be used before a deep dislike has set in.
• SilasBarta is undermining her attempts by posting comments about her, which she finds upsetting. In this situation, containment (e.g. asking him not to reply to her) is better than cure (creating a positive relationship).
• Alicorn rarely gets to see SilasBarta at what she would consider ‘his best’ – she is most aware of his posts about her, which she doesn’t enjoy.
• Alicorn thinks SilasBarta is very rational, and thus attributes his acts to him, rather than his environment.

Edit: list formatting.