The point is, many companies do need those nines and they count on AWS to deliver and there is no backup plan if they don't. And that's the thing I take issue with, AWS is not so reliable that you no longer need backups.
My experience is that very few companies actually need those 9s. A company might say they need them, but if you dig in it turns out the impact on the business of dropping a 9 (or two) is far less than the cost of developing and maintaining an elaborate multi-cloud backup plan that will both actually work when needed and be fast enough to maintain the desired availability.
Again, of course there are exceptions, but advising people in general that they should think about what happens if AWS goes offline for good seems like poor engineering to me. It’s like designing every bridge in your country to handle a tomahawk missile strike.
HN denizens are more often than not founders of exactly those companies that do need those 9's. As I wrote in my original comment: the founders are usually shocked at the thought that such a thing could happen and it definitely isn't a conscious decision that they do not have a fall-back plan. And if it was a conscious decision I'd be fine with that, but it rarely is. About as rare as companies that have in fact thought about this and whose incident recovery plans go further than 'call George to reboot the server'. You'd be surprised how many companies have not even performed the most basic risk assessment.
