It was because a method was discovered to bypass the lockout of stolen devices.

In other words the same old boogeyman they always use to justify this crap.

From what I understand this does not prevent use of custom ROMs, it just means ROMs built before it was done will not work anymore. I assume they can re-package old versions to work with the new configuration, I am not entirely sure though. There are discussions elsewhere in this thread with more informed people.

	▲	userbinator 2 hours ago \| parent [-]
		it just means ROMs built before it was done will not work anymore. From the article: Any subsequent attempt to install older firmware results in a permanent "hard brick" - the device becomes unusable This implies that not only does an older custom ROM not work, but neither does attempting to recover by installing a newer ROM.