Since JW's limit the field of mate selection to their own religion they really live in very small villages. Even village life is richer - socially. JW's discourage parties, picnics and other large social events - even big weddings. Even if you live in a large metro area you are dependent on being a member of a clique if you are going to meet eligible mates out of your own little congregation (village). If you are too fat, too flat, too short, too tall, - too skinny-too smart-too artsy - expect a life of celibacy. Or marry someone who will make you miserable for the rest of your life - because your completely mis-matched.
The one thing that served as a tool to bring young people together were the large district conventions. But they shortened those to a mere excuse. They eliminated refreshment stands & cafeterias that facilitated contact with new faces. Everyone is locked into an assigned regional group that is the same every year. Intermissions are "quickie" intervals where you can barely eat your sack lunch. As soon as the sessions are over everyone rushes back to their hotel so they can redeem the evening with a dip in the pool. Or else you have to jump on a bus to get back to your little village.
I know a lot of couples who look at each other and wonder how they ever ended up in a relationship with the only thing in common is a restricted social life.
The Watchtower ought to sponsor their own dating service if they feel the ad hoc groups are so bad. Or what would be so bad with having conventions of young single JW's where they could get their ears banged for a few hours in exchange for a chance to have some fellowshipe with other young JW's. I guess that sounds too much like YOUNG Mens Christian Association.
And then they wonder why they are losing their young people?