There's a bug open to make it easier to add external sites, yeah. In the meantime, until that can be coded (and it's a huge massive thing to code and once coded will require lots of manual admin oversight, which is guaranteed to make me cranky and put it off) this is the best way to measure how much interest there is in a particular external site being added either to the profile or to the <user name=foo> tag, so the votes are designed to measure interest in having that particular site available.