Thing is, if the US did have universal healthcare or whatever, the writers would have come up with some other contrivance to push Walter into cooking meth. It’s about Walter’s ego and his station in life. Also, it’s fiction, so they can do whatever they want with it.

It’s not like they had this idea, it came to life, and then they were bound by the rules of reality to write the show. They wanted to create a character to do all of this stuff, and the healthcare aspect was a way for the character himself to justify his actions.

You can tell by how Walter was given generous options to deal with his cancer, and turned them down out of pride.