It's partly human nature and partly part of the cult mentality to take friends for granted when you always have a veritable smorgasbord of people available to fill out a crowd, whenever you need one.
JW's typically have a congregation of people available for whatever event they put on. Many don't realize or maybe have simply forgotten what it is to have seek out and make friends from scratch as well as keep them. That's why they are often so inclined to toss you away if you simply stop attending their meetings. There's always someone else in the crowd to take your place.