He hasn't taken a deep-dive into the protocol, as you can see from his quote regarding 51% attacks
I agree. He seems far from an expert on bitcoin, though you would think he would have more knowledge. Though maybe he's looking at it from a neutral position and we are biased slightly as I guess a 51% attack could happen so it could be an issue though likely wont. And if that's his only issue with bitcoin its not too bad at all.
I would agree. You can know a lot of IT, a lot about encryption but if you haven't really looked in lots of detail about the protocol, it is easy to be misinformed.