Part of my job is working on trying to make these models productive for the large corporation I work for. It's a lot of throwing tomatoes at a wall and to a degree I see the issue he is talking about output seemingly having a certain ceiling.
At the same time in no part of his post is any code snippet or anything to latch on to of "the model performed poorly here when it should have done this" - this style of criticism seems to be a pattern of most of these "the LLMs will never work" style posts on blogs and twitter.
They obviously can perform better than autocomplete and in my own day to day development build out huge portions of a codebase that I would have expected a junior or midlevel engineer to perform at.
How are we really supposed to grasp their actual capabilities when no one will actually cite specifically what mistakes they are making.