I know what you mean. The role of the alpha male has diminished in mainstream anime and manga. I asked around and still couldn't come up with the kind of argument Hokuto no Ken is. Actually, the only somewhat recent and popular manga that revolves around manliness was Vagabond.
I still don't think the situation is as bleak as you imply. That is simply because there are all kinds of manga, and as there are stories about little girls who stop bullets by peeing at them, there are also stories of naval warfare and the destinies of the men involved.
It's still sad how the unforgiving, violent and almost evil manliness is less and less frequent. But in my opinion, change is better than stasis and as men go away, girls take their place. The roles of female characters vary a lot more than in the eighties. I hope.