Github.com allows people to host pages on their custom domain and that may include not just static html but also blogs based on jekyll and hackyll see an example: http://bibhas.in
Sourceforge also allows people to host sites and pages even forums and blog sites that have a database
This is what bitbucket does not allow, and lack of this feature has put me off as because with bitbucket I cannot have my own project's good looking start/home page in bitbucket which I can still have in both Sourceforge and Github
In bitbucket the project's home page provided on a custom domain - which I will get for my project looks like a scientist's diary and I cannot show this to normal/newbie people who will be visiting my software project's homepage to know about it, I need a better looking startpage and hence I have decided to switch to github currently for this project.
if in future it allows the same, please let me know, I may create another project here.. just because bitbucket allows private repos which github doesnt allow yet on the free quota.