- OpenMoko (2006)
- Symbian (2009)
- MeeGo (2010)
- Mer (2011)
- Jolla (2011)
- Tizen (2012)
- Ubuntu Touch (2013)
- Firefox OS (2013)
- Web OS (2013)
So it is a bit more than just lack of marketing.
- Maemo: open middleware, closed many applications and some drivers
- OpenMoko: closed drivers
- Symbian: was it ever libre?
- Meego: same as Maemo
- Mer: this is actually open AFAIK, but no native devices I know of
- Jolla: Android kernel (closed drivers), closed applications
- Tizen: ?
- Ubuntu Touch: Android kernel
- Firefox OS: Android kernel
- Web OS: ?
Only a couple of the above really matter in this light.