"It does offer the question: what do you do when you reach V1/rotate and nothing happens? I've made my mind up on what to do. Especially when there is a serious question of stopping"
Surely you abort. If the aircraft doesn't rotate when you ask it to then: idle, max reverse then start braking. May even then call for maximum flap to add a tad more drag. You may be a bit over V1, but you're only going to trickle off the end of the runway. Moreover, if your perf is biased for a balanced field or doesn't take any account of actual runway length you may well be able to safely stop on the runway despite initiating the abort well above V1.
Undoubtedly when V1 = Vr then it is a no-brainer. You may be unlucky and bend the gear if you cross a gulley, but if you try to fly in an aeroplane that just doesn't want to fly then the outcome will be inevitable.
Not an everyday scenario, but I don't subscribe to never aborting above V1.
This is simply my response to the question above about a specific problem, not the reason these poor souls perished.