I think you are taking a rather narrow view of this. You are acting like there is no danger involved in experimental treatments. What about all the crazy drugs that have been discovered to have horrible side effects? You are also ignoring the rights of people who may have religious objections to not be subjected to this kind of thing. I repeat you have points that are valid. But there is more than one side to this.
If you are going to die without it, what difference does it make what the side effects may be? They have to be preferable to sure and certain death; God may help you, but He does not appear to want to help fools that will not avail themselves of all that He has made available to human medicine.
I take the view that life is preferable to death and that medical technology is advancing at such a rate that a "crippling illness" of today may be a "mild inconvenience" or even less tomorrow.
When you're unconsious or delirious, you are unable to state your consent or withold it. On the principle of "get them stable first and find out what they want to do when they're able to state their wishes," this preserves as many options as possible.
This regulation does NOT apply, by the way, to people wearing the *metal* DNR or NHM bracelets. They won't usually make it to the ER. Those with religious objections can purchase one of those, and die with their convictions intact.