>>If the hatch were still oepn it would not longer be a launch accident and other means of escape were possible. Which bit of LAUNCH ESCAPE don't you understand? It is not intended to help before launch, or in flight, or during descent.
Only 25 seconds elapsed between the detection of the fire and the explosion, and even this was unusual. Generally there is little or no warning in a pad explosion. No ground egress system permits escape of all personnel from a large launch complex in less than about two minutes, and I am unaware of any actual historical pad explosion in which that much warning time was available. If there is even a detailed failure analysis that identifies a mode in which a catastrophic explosion actually occurs after a warning period long enough for ground egress, I would be interested in seeing it.
It's quite true that the Soyuz booster is quite reliable; as a result it had just one catastrophic explosion in which the LAS permitted escape. The LAS also caused one fatal incident. Redundancy adds complexity and creates additional failure modes, and if the failures where the redundant system causes as many failures as it mitigates, then redundancy doesn't help. There are situations when redundancy is an appropriate method of increasing reliability, i.e. carrying a spare tire in your car, when the mode of failure is understood and changing the design to eliminate the failure mode (i.e. run-flat tires) is not feasible because of cost, the failure rate is known with some accuracy because the component has actually failed multiple times in testing or actual use, and the failures induced by the redundancy (i.e. people injured while changing tires) is very low. However most launch vehicle failures, once the failure mode was known, were completely prevented by relatively minor design changes. So the most effective way to improve launch vehicle reliability is generally thorough flight testing of the critical design elements, simplification of manufacturing, servicing and maintenance to minimize critical tasks, and effective quality control (on the actual hardware, not the paperwork).