Turning off comments would have had the same effect. You can't spam if you can't speak. A project update explaining why comments are no longer available, and emailing the project creator to start a conversation, would be good next steps.
You also can't post a comment if you don't have an account, so banning the account would be a reasonable stopgap measure; this step wasn't mentioned in the blog post. If they're flooding accounts, then ban the IP. If they start switching IPs, then you can start making excuses for Kickstarter.
You also can't post a comment if you don't have an account, so banning the account would be a reasonable stopgap measure; this step wasn't mentioned in the blog post. If they're flooding accounts, then ban the IP. If they start switching IPs, then you can start making excuses for Kickstarter.