This is how you turn e-mail to crap - not how you hustle.

If they had tweeted to him back or DM him (i.e. used the same medium as him) then I understand. Sending unsolicited e-mail that capitalizes on a competitors stumble just makes you look petty IMO. Also, people should want to consume your service because they LIKE what you do more than your competitors not because you are pouncing on another's misery to flog your own thing.

Please do not encourage this kind of behavior by writing blog posts about hustle.