What if they're doing it deliberately, because they personally believe in allowing users to install customised firmware, and feigning ignorance/incompetence? They certainly wouldn't be able to do it "officially", so they work around it. Once everyone else knows, they'll admit their mistake and "fix" the problem, but add another way in?

Of course it could just be incompetence, but it's particularly interesting to consider the alternative. Seeing all the other companies who have leaked keys, datasheets, and other useful but officially proprietary information on their products, really makes me wonder. Also, those vulnerabilities which allow for jailbreaking and rooting of locked-down devices? Are they also there deliberately? For some reason, I really hope so.