That's not full reverse engineering. They're removing the protection, with a clearly defined goal they can look at to see if they're done, and that's all.
Very different from trying to figure out everything a program does.
In the case of peyta: is that necessary? There are 2 pieces I know of someone would want to change, the Bitcoin wallet and removing the Killswitch.
Surely this is easier then a full understanding of the code?
And still ppl who crack games do it very often. They start with a obfuscated binary, decrypt it and patch it to remove the protection.