As a concept, people know that there's a real person behind every application. But it's not until moments like these when they're actually confronted with that person. Much less offered a deal for trying to rip them off.
The message would thank you for trying out the game. It would usually talk about how the game was awesome and what you were missing out on. It was clearly genuine. You didn't feel like you were purchasing something from some giant company trying to sell something. You felt like you were supporting some people who were passionate about the art they created.
I miss this about games and think it may be the reason that I've sort of stopped playing the big titles after 25 years of non-stop gaming. I find myself much more drawn to independent developers on the mobile platform or the wonderfully simple and innovative games from small teams.
I expected "something nicer" maybe not using the word "stealing"
Still, my paranoid side thought of something:
"Oh, they're giving away this code so we give them our contact info, then they know who pirated the software"