I’ve always wondered how it’s possible that some iLok protected plugins, like Eventide, Softube, and Slate Digital, have been cracked while others have not. Can someone explain?

 

It's like mafia: the more you pay, the more protected you are.

 

When you crack a plugin you (in most cases including iLok based protection) modify this plugin only. Only plugins you have modified are cracked. To crack all of them you have to modify every plugin separately. It is not an easy task. You don't touch iLok itself when you cope with iLok protected plugins, you cope with every plugin separately.

Some developers of plugins protected by iLok choose minimal protection, some of them choose advanced one. Tha latter plugins are harder to crack. Some developers use iLok and they own tricks or (may be) even mix different protections. The latter are even harder for cracking.

Sometimes installers of protected programs aren't easily available. You cannot just download them. Somebody (a legit user) have to supply them to crackers. That means you have to buy a plugin and then supply it and all the the related info to crackers. There are not many people who are ready to do it. UVI plugins stayed uncracked some time for this reason.