the usa seems to think handing out guns is completely ok
Please link to something describing this gun hand-out program, especially to one that ignores existing federal laws about not letting crazy people buy them.
The real issue there is that crazy people aren't called crazy any more, because it's politically incorrect to do anything other than mainstream them and hope for the best.
laws that promote *irresponsible* gun use
Please cite actual laws that promote irresponsible gun use. Specifically.
the second amendment even says a "well-regulated" militia (meaning "well-trained").
Which has 100% nothing to do with the protections the 2nd amendment guarantees individuals. It's BECAUSE the founders knew that having a standing army and/or people ready to stand up a be an army was always going to be necessary, that they didn't want the government and it's approved soldiers to have a monopoly on the ownership of firearms. You've talked about this before, and walked away from the conversation whenever you're confronted with the actual history of the matter. Choosing to take the amendment's language out of context doesn't change things. The second amendment doesn't require training any more than first amendment requires you to learn how to capitalize your sentences - something you still haven't figured out. Both of those amendments, like others, exist to prevent government interference with your rights, not to limit them. That you think it's the opposite shows how you completely misunderstand the constitution and its history.
a gun is dangerous and requires responsible training
Just like kitchen knives, swords, horses, and matches, right? Please point to a single other place in the constitution or in any of the contemporary writings of the people who wrote it and the amendments where there's even a HINT of concern about it being part of the nation's founding charter that people aren't allowed to handle dangerous things without government training. Farmers even then were using black powder explosives to remove tree stumps in their fields. Which amendment addresses that? Please, be specific.
how can someone who is a responsible gun owner defend this status quo?
You mean, the steady, multi-decade decline in violence that happens to involve the use of guns? But more to the point, people mis-using cars kill a lot more people. People using objects like knives and baseball bats kill far more people than anyone using any sort of rifle. How can drivers and baseball fans defend this status quo, right? Right?
you would think gun owners would know more than anyone the need for responsible training first
Right. People who use all sorts of potentially lethal devices and substances generally know to learn about being safe before doing something dumb. But of course thousands of people die and kill other people doing dumb, reckless or malicious stuff with non-gun items every year. Your completely phony obsession with a fantasy notion that, of all of the dangerous items and activities in the world, ONE of them gets a constitutional amendment mandating safety training, and that that amendment, unlike all the others which exist to limit the government's reach exists to limit individual rights - it's laughable. Spend five minutes studying the entire purpose of the constitution, and you'll (if you're honest) understand that you have it completely backwards on the one amendment you're cherry-picking and twisting to suit your agenda.