For the people who don't know, I was a charter member at OSGeo since 2006, and I recently served on the OSGeo board of directors.
The main reason for leaving OSGeo at this point in time is that I feel that the recent communication that has been happening between OSGeo and LocationTech is very unprofessional and disrespectful from the side of OSGeo. I must say that Andrea Ross of LocationTech has been super professional, I'm not sure I would have been able to do the same in her position. This communication has been mostly on the conference_dev e-mail list (but also on discuss). It has been really hard for me to read that communication and not speak up publicly about it. I'm glad Cameron Shorter did say something about it here: https://lists.osgeo.org/pipermail/discuss/2015-November/015310.html on which I fully agree but I feel like a lot more people involved in OSGeo should have said something about this. I encourage everyone to read the relevant November threads in the archives https://lists.osgeo.org/piperm