It's a personal blog. The author has no obligation to keep it to the standard of a trade magazine. Blogs are supposed to be subjective and it's okay for a blog post to be harsh if the author feels so.
For me it's not just the lack of professionalism but the writing makes the author sound pretty junior and inexperienced with how the world works. Not that there's anything wrong with that (we've all been there). But it can cheapen the discussion and feel like what really needs to be untangled is overlooked by stuff like "I was upset because they changed the UI and then I got used to it." Not very interesting details and not very useful thing to discuss.
