> with no appreciation for what it takes to build robust failure-tolerant systems

It's a risk aversion issue. Large software projects are horrendously difficult to get right, and managing airlines is a horrifically complicated kind of project. Fault tolerance aside, just correctly modeling the problem is a mess and by the time you have a correct solution, the problem itself may well have changed. So you end up having to throw a lot of resources at a very complex problem and know that you may entirely fail at it, which is not the kind of gamble execs love.