A part of my job is to review CVs and select candidates to interview for my team. The first thing I do is check to see if they have a github account, and if they do I check their projects. Anything that looks relevant gets a quick inspection. It makes difference to whether they get an interview, and it makes for some topics of discussion during the interview. It confirms for me that the candidate is in fact actually interested in the field, and shows be the porential quality of their work.

If you think nobody ever looks at your public code, you're wrong. It's just like wearing a bathing suit at the beach or pool: people look.