I think the only holiday that JY offer where you have to share a room for a few nights is the Kenya Safari, this did work out well for everyone, I think this was only because it was literally a couple of nights on safari and at the 2nd hotel you were back to your own nice room on your OWN........
At the end of the day JY are between a rock and a hard place, they offer themselves as a tour for single travellers, and need to make the money...they can't not take say block bookings, like when I travel with a friend we are both single travellers...my concern would be if there were groups of couples ie male/female relationships as that would I feel change the dynamics of the group.
I know of one man who travelled with his lady friend but had separate rooms, but I didn't get the feel that they integrated into the group well. So I can't see something like that working well in a group of single travellers.
That's the other issue at times,what does single traveller mean, it means different things to different people, I am a single traveller but I am NOT single I have a hubby (30 years) touring is his idea of hell, he just wants to chill out after his busy working year, I on the other hand don't work as hard as he does so I want to see and do things. We still holiday together but we also holiday apart it works for us..
Cindy