Yes, it does raise the "herd of cloned sheep" question.
But I wouldn't worry too much. It's open source, and using the hosted version means that only that one copy has to be fixed. It is unlikely to ever be a problem on the scope of, e.g., out-of-date Wordpress installs.
A good alternative for developers is username.github.com, particularly if you already use GitHub for code samples. You create a repository named "username.github.com" and then set up GitHub Pages for that repo. (There exist other sites suited to e.g. design portfolios.)
But I wouldn't worry too much. It's open source, and using the hosted version means that only that one copy has to be fixed. It is unlikely to ever be a problem on the scope of, e.g., out-of-date Wordpress installs.