When I was training in the ED we had many patients who should have waited to see their PCP during office hours (the war stories could go on for days), but they were not the only problem. One of the other comments mentioned EMTALA. While EMTALA was legislated with good intentions, I'm sure you are aware of where good intentions lead.
Some friends of mine have a small business. They work as a group staffing local ED's as contract physicians. Due to EMTALA, they are required to assess everyone who comes through the door and requests it. Once you've taken a history and examined the patient you are allowed to tell the patient to see their PCP if the visit is not emergent or urgent. But you've already assessed the patient, so why not just go ahead and treat? Most ER physicians will.
As a result they see patients like the teenager whose Mother at 3am Sunday morning decided she was worried senseless about the rash her daughter had had for three weeks. (Possibly the senseless part came before the worry.) They see really sick people who need to be in the ED. They see people after accidents. They see people who do not have a PCP or cannot afford an office visit. They see what we call the frequent flyers, who show up over and over and over with whatever misbegotten excuses they can imagine.
And fully one third of those people will make no attempt whatever to pay for their treatment or the bill will be refused by Medicare, Medicaid, or insurance because the visit was not emergent or urgent. In what other profession does the government mandate working for free?
For those who are truly ill and in need I, and most of my colleagues, will jump in and help without considering payment. But charity should not be mandated under threat of prosecution.
Of course, fear of being sued will stop some from helping, and that is something that should be addressed, too. Sweden does have what on first glance looks like a decent system in place for that.