I don't find any benefit for programmers to promote their work via blog posts.
There are plenty of forums and platforms dedicated to the programming community where programmers are able to post their work or improve the code of others and gain publicity...
Agreed. I can imagine a website where you post some of your code as a portfolio when you're looking for a job... wait for a second! There already are hundreds of websites like this. I don't want to be a killjoy but this blog doesn't have a huge potential.