They already have and it is completely fine, I’m honestly happy that people find Colibri useful and enjoy using it, simple as that. If you enjoy using Colibri and can afford to buy it through the Mac App Store later, then that’s even better.

I must point out though, that – as you’ll soon see in the questions regarding Sandboxing – there is a reason why applications are strictly verified by Apple in the Mac App Store; it is most likely safe to assume that apps downloaded from the Mac App Store are thoroughly inspected and are highly unlikely to contain any piece of malicious code – when you upload an app to the App Store, there are automatic checks beside human reviews that are supposed to catch such malicious behavior.

If you decide to pirate Colibri then consider using verified, trusted sources as some mirror sites / repackers tend to inject malware into their .dmg or .pkg installers.