The criticism of brew's instructions is warranted to be completely honest, they could certainly word that one sentence a little better. But the way I interpreted the parent comment is that it makes Fig employees appear less capable because they don't understand intricacies of the shell, but as I described in my other comment, not everyone has to be an expert of the shell. Brew is not a "power user" tool, it's a package manager for macOS. Instructions should be clear for all types of users.
I meant that a multitude of employees had misunderstood the instructions. If you take a breath and think about what that first line is doing for a few seconds, you’d never put that into your profile.
I think the article says that they discovered the issue because of Fig users contacting them for support with it, not from Fig developers doing it themselves.
You're right, it's not a great look for any project to post a criticism of another, largely unrelated project. But where else would they post it?
Posting it like this helps it get the exposure it needs. I think posting it to brew's bugtracker would just get it lost.