I think this is a misunderstanding that has been blown out of it's deserved proportions. The people involved were members of a recreational club organised by members of the British army - this is true. For this expedition however they were just travelling "as civilians" and not on any sort of official training expedition. Presumably all of the paperwork etc. was presented on this basis.

The entrance to this particular cave system was known to have a vulnerability to flash flooding and this contingency would have been planned for which is why the food etc. was available.

Cave diving is a very specialized activity and over the years has had a spectacularly high death rate even amongst experienced cave divers. This is why the British team were willing to wait for the two British divers - one had previous experience of diving in this particular cave and the second was also highly experienced. Since they had the capacity to wait it out there was no need to rush and better to wait for experienced divers than risk the deaths of less experienced rescuers.