Facebook, Twitter, YouTube and Reddit will skate by with inertia for years to come no matter how suicidally they behave because they have mass appeal. Losing one audience doesn’t matter because they have millions of other audiences. You start up a social network that interests mainly technical people and the journalists that report on them, well it’s just not going to thrive because after the honeymoon period is over, the network just starts to look stale and slowly die off. E.g. Google+.