On the contrary, zipper merging works in every developed country except one.

More and more of my feeds are articles by Americans, decent people themselves, explaining to me why any possible progress will be forever possible in America.

This one was so over the top that I really thought it was a parody. You think the US shouldn't bring in zipper merging - because you expect a wave of murders? And you get why people are so angry about a completely logical and safe driving practice that would speed up everyone's lives if adopted?

It's Stockholm Syndrome. None of what you say is at all sane.