Most of the reasons are good, but how can anyone keep a straight face while they present changing strategic priorities as a big-company problem? Don't startups do 90-degree "pivots" of the entire darn company just as often? The ten startups I've been in all got jerked around far more than the two big companies, and I get the impression this is even more true in today's startup culture.
I think the issue around this is in big companies you rarely see the reasons for the shift in priorities. At least this has been true in my experience. When priorities shifted in my last job all we got in explanation was some buzzwords and a 'trust me'. At my current startup job, when priorities change I get all the information that lead to the decision, and can also participate in making the decision.
