I don't pirate games either, but that doesn't mean I don't understand the security issues surrounding them.
You need to realize that a program is just a file on a computer. If you think of it as a bunch of bytes that you could read and change, then you will realize that a person with enough skill can make your program do whatever they want.
Unless the hardware has some security measures also, such as
Trusted Computing. But the cure is worse than the disease.