Rachel Andrew had a short but very worthwhile post about how much the web has changed over recent years from people owning their own playground on the web (in large part via personal blogs) to people handing over their content to third parties like Medium and CodePen (to name a couple).
I agree with Rachel completely. Nevermind the fact that places like Medium don’t seem to have a workable business mode, owning your own content makes from a number of points of view. First of all, these sites never offer any real return for people’s content. At best, you’d gain some notoriety by virtue of the community they built - but that was even a big if. At worst, you handed over your content in return for nothing to a company to make their own money off of and now have very limited control over it (beyond whatever tools the company may provide you).
As we move our code to CodePen, our writing to Medium, our photographs to Instagram we don’t just run the risk of losing that content and the associated metadata if those services vanish. We also lose our own place to experiment and add personality to that content, in the context of our own home on the web. - Rachel Andrew
If you are creating content - be it code or writing or anything else - value it by owning it. Especially today when owning your own blog is both easy and free (may I suggest Jekyll!).