a diff I see missing from bitbucket is the visualization - heat graphs/maps of my activity on a project or across projects. I know it wasn't there early on, but I've known more than a few people that keep committing to a project on a daily basis because they can keep their streak going on the visual chart (on github).

It's not really one particular feature, but a whole mess of little things that, collectively, will keep github 'default choice' for a lot of folks for a long time coming - it's inherently a bit more 'social'.

That said, I'm in agreement with your view that most other services have most of the main same features anyway - I prefer bitbucket for my projects, but... I'm in a minority. This sort of feels like MS Office vs OpenOffice 15 years ago. Yeah, technically there's a lot of the same stuff, but there's enough 'missing' features from multiple users' perspectives that the larger player still 'wins'.