Most source code will also be badly readable if you print it out ;)
So should we change our use of C++ to make it more GitHub-friendly? Or should we fix GitHub to properly work with the C++ source code that already exists?
I think it's not an issue of Github or not Github. Either you think of code as plain text first, or you think plain text is just another way to present it. I think of code as plain text first, and thus I like programming languages that don't need to be analyzed to be displayed properly. Other people may not think the same.