> Is it not as crazy as it sounds for most users?
It's primarily lots of Byzantine rules in small print buried in long policies that few people read and even fewer memorize. If you are lucky and are conscious when you need to use a policy to visit a health care provider, you can bring your policy with you to ensure you follow it, but it's not always that easy. The health insurance company claims they told you how to follow the policy, but they don't make it any easier than they legally have to.
If you skip a rule (like calling your health insurance company before you visit an emergency room), that might violate your policy.
If you visit an "out of network" hospital when you should have visited an "in network" hospital, you may be liable for the difference in cost (which is huge due to health insurance distortions in the medical market).
If you try to go to a medical specialist without first going to your primary provider (as defined by your health insurance company), they likely won't cover it.
There are usually dozens or hundreds of pages of these rules in booklets that you get when you join an insurance policy.
If you don't know about / forget about a rule, you are responsible for the costs associated with the violation.
It's easy to unwittingly ask a health insurance question about your policy to the office manager at a doctor's office (who isn't qualified to speak about specific health insurance policies) and getting bad information that you then assume is good.
> Why aren't people marching in the streets?
I think most people see this as a "free market" problem (since 60%+ are covered by their employer-sponsored health insurance), not a political one. ~20% of Americans are covered by Medicare (the retirement-aged national health coverage) or have military veteran benefits, which are generally considered pretty good (unless you listen to political arguments). How would "marching in the street" fix a problem that people have with the "free market"?
The remaining 20% are among the most politically apathetic. We are lucky to get 50% participation of the voting-eligible electorate, even in presidential elections (which have higher turnout than other elections).
I think lots of Americans pride themselves on being stubborn and pretending like painful things aren't painful, then trying to ignore them.
Lastly, I think most Americans simply don't think that marching works. Rural America doesn't march. Urban America only seems to march for generic social justice causes, not for specific policy improvements.