It is not uncommon for individuals and even entire organizations to rely on some third party platform to host all their thought-leadering. Medium is the common choice, but many use other platforms as well, such as LinkedIn.
While many argue that the reach is better and it is easier than self-hosting, few consider what will happen when their chosen platform goes away (or the platform chooses to purge you). After all, the web is littered with the corpses of platforms populated by content that you wrote and that we will never see again.
The death of GooglePlus earlier this week is the perfect time to re-up this from Adrian. With the rate of site deaths or just general data loss, like in the case of MySpace and all the music, this will never stop being evergreen content. Seriously, listen to Adrian and do what he tells you. Start taking control and ownership of the content you create.