It is somewhat difficult to lock your own device so that you cannot factory reset it. You wouldn't just have to lose the passcode, you would also need to lose the credentials to your iCloud account as well as your purchase receipt for the phone. Then you become indistinguishable from a thief.
I am okay with Apple's choice on this, as I prefer the security and the theft deterrence. I keep several methods for recovering my iCloud account, and I keep the receipt for my expensive devices.
Does activation lock even apply to Macbooks?