Okay, yeah … I am very far from the internal discussions and considerations so very likely I don’t have full view on this but here are some additional thoughts on your response.
Re: Alternative Reasons
Agreed. There could be a number of reasons. Examples: 1) People have also tested all the options regardless of where they are hosted and come to a different conclusion about the best offering; 2) People need something that works with MySQL ; 3) People have an easier time installing an alternative, etc … All that said: I think we have to consider that Github is where devs search for projects and this is the “top of the funnel” and I have to imagine that many projects languish and, again, don’t get the attention they deserve because they aren’t hosted in the place for most of the open source software in the world is hosted.
Re: Workflow Reason
I know workflows are annoying to have to rebuild so that’s why I mentioned that in the cons. It’s hard for me to predict whether benefits of the possibility of dramtically increased adoption or community involvement from being on Github outweigh the nuisance of migration but my hunch is that it would. It’s feels like something like the location of a restaurant: Hopefully people will travel a far distance to try the good food they are hearing about at a remote location but it’s much more likely people will come and the restaurant will win if they are serving great food and located right downtown where there is already lots of foot traffic and close to everyone’s homes so it’s an easy walk.