I should have known better than to just write "my first thought" without further qualification... While the author may not have written "purely visual", there

I should have known better than to just write "my first thought" without further qualification... While the author may not have written "purely visual", there is this quote, immediately preceding the claims quoted at the root of this thread: "At Daedalean, we have built a system that uses nothing but visual input, just like the human pilot in that almost-uninstrumented aircraft from 80 years ago, to..." [my emphasis.] So, while the author does not use "purely", he states something equivalent to doing so. Furthermore, the entire tenor here is that they are not using any of the modern technologies that are currently central to commercial aviation (why he wishes to stress this fact is another issue altogether.) My point here is a bit more subtle that pointing out the obvious: that automating VFR flight will not cut it (with or without GPS and other aids, for that matter.) It is, rather, that there remains a huge gap between what they have achieved so far (or could be achieved just by integrating GPS and similar aids) and what will be required to achieve the level of performance blithely suggested in the comment about landing on the Hudson river. UPDATE: I made that last point in a different comment; what I was wondering here was why the author seems determined to point out that their current system does not use GPS etc. - perhaps because any of that would make it look less like AI?