The post opens with the classic just brew install blah, and immediately runs into the problem of people not having brew (or some other package manager) preinstalled and ready on their computers. It's the walled garden problem.
And it's not a trivial problem. And even this meta-level argument is not necessarily straightforward, because it comes with serious trade-offs.
And .... unfortunately even one level up, where it should be straightforward to see how a walled garden monopoly is bad (as the consensus on rent-seeking being bad is pretty strong in economics) people mostly don't care about this issue, because they don't connect it to the value of "more power user freedom".
People start to see the value of right to repair tractors, people see the value of the first sale doctrine, people see themselves as temporarily embarrased rich gentlefolk, but they are afraid to see themselves as just a few commands away from a power user.