And that's reason #1 we don't use Github. Assembla lets us host all of our git, SVN and Mercurial repos for free.. currently we have 32 and counting, no issues ever, without paying a single penny.
Maybe, but GitHub's pricing model encourages sharing, and that's a good thing. Think of how many repositories might've been private and not benefited thousands of people.
Granted, the prices might be steep/strange, but I see no problem in charging for things that people don't want to share on a social code sharing site.
Sharing doesn't necessarily mean someone cloning or contributing to your project. I find github useful because it lets me read other people's code both for evaluating potential co-workers and getting better at my craft.
I've learned a lot from reading other people's code and I still think it's one of the best ways to learn new languages and techniques.
Even with some of my more obscure projects on Github (like a ZNC module that sends IRC notifications to my phone via Notifo) have garnered some observers, forks, and pull requests with features or improvements that I probably never would have gotten if it had either been on my own repo hosting.
I'd love to use Github and all, Github's cool. But I can't justify paying that much for private repositories. Even with all of the annoying junk on the site, Assembla's free plan won hands down.