I agree with you completely. On my trip in May we did have a couple of friends, but they did mix and were very sociable with others, they also had their own rooms. Married couples should not be part of the holiday. So many people seem to say what a great company JY is, sadly my experiences did not reflect this.
The group was 35 (I thought it was meant to be small groups). Our Local tour guide was dreadful, the only time he seemed to be happy was on the way back to the airport. We had a lady who sadly had dementia on our trip, we all felt responsible for her as our tour guide didn't seem to have a clue what to do.
I contacted JY on my return and was not given any answers, just that they would forward the matter on. No results yet, this prevents me from booking another tour with JY, they are expensive, I feel I would have been better to go with a regular company, I would have, had better support, all around.