There is nothing "hipster" about it, it's a perfectly valid technical decision for someone who doesn't want to fuss with a janky, complicated WordPress installation or writing raw markup for each blog post or writing their own CMS. Frees up more time for developing things which are of any actual interest.
It makes getting good, scalable performance basically trivial. Static content distributed across CDNs means someone else solves that problem for you at low cost. Forget SQL injections and usually forget XSS. If you need a comments section, you realistically need outside help to filter out spam anyway, might as well use something like Disqus. Also, very few moving parts to break after deploy.