Many adventure/activity holidays are geared towards individuals... friend did diving holiday where individual travellers were the norm and that was what everything was geared towards. Idea was that he was there to dive as much as was possible so 'couple time' wasn't really catered for. Although more or less all the folks there were there on their own it wasn't because they were necessarily single, they just weren't there as part of a couple... socialising in the evenings yes, but no singles night or anything.