He quotes a post from Drew thanking Brandon for his remarks, and spends the rest of the essay saying the thanking is an uncalled-for "level of retribution", "effective slander case". But both exchanges between Drew and Brandon (the one in 2007 as well as the one in 2018) seem friendly to me.
My impression is that when linking to Brandon's post, people are usually saying "a company can still succeed by offering something that was previously possible, by making it easier to do" and "don't be discouraged by criticism saying it's already possible". They're not saying that Brandon was a bad person or that his feedback wasn't useful or anything.
Zed also makes a big deal about Brandon not being able to delete his post - but I remember dang mentioning that they would delete posts when asked, but everyone so far has agreed to a compromise of removing the username but keeping the post, which does seem like the best solution in a case like this (where the content of the post has historical value but the author might want to disavow it).