I've never seen his github account before but I expect that people following him there are doing so because of the content he's putting out. His blog has been on the HN Frontpage many times and has a book about developer career building.
My github account isn't as pimped out as his, but marketing yourself isn't toxic, it's smart.
i honestly dont even view my github readme as "marketing yourself". most pple dont even go to an individual's profile in the first place, but if you do its kinda like a cute little myspace thing where you can let people know you as a human being and be a little quirky. i certainly dont hold myself out as an authority on writing the best software in the world and hey if 40k stars on the react-typescript stuff doesnt count i'm alright with that