I don't believe in people being complete idiots. Any TV series has many people behind it, therefore it is highly likely that the series Friends was conceived deliberately the way it is. All Friends main characters are singles, some of them even divorced. They practice promiscuous sex and are constantly unable to find a decent partner. Their problems in finding a partner are never explained, on the contrary, their being constantly singles and practicing promiscuous sex is depicted as something normal, as natural and healthy. At the end, some of these friends become so desperate to decide marrying between friends. This series instead of teaching people how to find a partner, cheered losers of any kind to remain singles and don't worry about it.