The intention is good, but in practice I think it's mostly useless because:
* The reports go to the AS operator, who in most cases are not the actual admins of the vulnerable software. Some hosting providers such as Hetzner and Manitu have scripts in place to forward reports to the respective customers, but most don't since it involves a lot of parsing of the email (which is not in an easily machine readable format).
* The emails often warn about security issues that may not actually be problematic (i.e. merely warning about some open port that may be intentionally open, and especially if you operate, say, a honeypot), with no way to opt out for specific hosts/ports. So you can only really filter them entirely in your mail client which I think most people do.