I think this increases the threshold for people to use Akismet (even if it's still free for personal sites) and Akismet plays such an important role in helping to keep the entire WordPress ecosystem healthy, I'd rather see Automattic monitise other products/services. If this leads to less installations of Akismet it's probably not to the benefit of WordPress or Automattic. Not to mention the double standard apparent in the plugin repository policy. Like Chris said, there's no way other plugins could get away with a similar protocol.