I think there's room for the perspectives offered by both formal and informal writing.

Given the informal context, reminiscing about first job interviews with friends, I feel that the author wanted to share that setting with us as readers.

It may not have been the same decision you would have made, but take it as a chance to learn a new perspective rather than opening with hard criticisms.

I disagree, I don't think the style was informal, I think it was simply poorly written. There is a difference between the two. The blogger never purported to be a good writer, so I don't fault him for it and I was able to get the gist of what he wanted to say, but it wasn't well written..

Informal is totally fine, but I found the relatively low writing quality distracting.