A lot of it has to do with options. Not good or bad, but options.
You go into a store and want to buy milk, and instead of there being the local milk selections there is now 50,000 different choices. So we always seem to hold out for that more ideal option and never really select one.
This might be where modern dating is going. Fight Club talked about the single serving friend. Tinder style dating has turned us into single serving partner.