I find it interesting the number of responses that had success after gathering e-mails. If your 'Show HN' asks for an e-mail here, everyone gets incredibly angry and lets you know they stopped looking at your product right away.
Asking for emails allows you to target people who are more likely to engage with your marketing, while people who find this annoying would probably be more critical of the product and in general are more picky. In the end they still give you engagement in a form of comments, so it's a win-win. Similar strategy is leaving easily spottable typos in your post so that nitpickers can't help but comment on it.