Matthew Ygelsias on why it's good that under Obamacare, some people won't be able to keep their existing plans. One fact that critics of the Affordable Care Act overlook is that before it, you had no guarantee you could keep your existing plan. In fact, you had a great likelihood that if you suddenly got really, really sick (and therefore really, really expensive for your insurer to cover), they'd try to find some way to boot you out or not pay all the benefits you thought you had coming.