Real question for self hosters: what kinds of applications are you running where you feel you need this?
OwnCloud - I just don't trust an American company to host my data. Now, is my small UK based host as likely to be as effective at protecting my data as DropBox? Maybe not - but they don't have a proponent of torture on their board, so it's swings and roundabouts.
TT-RSS - I couldn't find a decent RSS manager which I liked. TT does the job - and I'm not worried that someone will decide that Google+ is better and force me off.
Ampache - all of my music is stored as FLAC, which can be a PITA to transcode and/or stream. This sits on a box at home and I can listen to my music wherever I am. I'm not reliant on a corporation who might decide that my music isn't licensed correctly, or they don't want to support my hardware, etc.
Personally I use WordPress rather than Ghost - it's more flexible for my needs.
It’s pretty cool, basically like TT-RSS but it looks more modern and is integrated in ownCloud. There are also apps for almost all platforms, like apps for Android & iOS which download all articles (and even podcasts) for offline reading.
The reason I selfhost is this. We are on a rapid path towards home computing devices being nothing more than dumb terminals where some server in the distance hosts your OS, files and apps. All, of course, proprietary so as to make switching painful. I DO NOT WANT THIS. So, I use and root for the technologies that I want to see win. I want complete and unfettered access to my files.