Oh, I see. I misread your earlier comment as asking what I thought you advocated, rather than why I thought so. Let me try here to answer your actual question there.
I consider generally that to have left the Imperial flower intact through a negotiated surrender - even if achievable which I seriously doubt - would have led in about a generation to a dangerously resurgent sense of revanchism, as actually occurred in the 1960s, but was a matter largely of fringe comedy because the 1960s in Japan were not really such as to make anyone other than cranks wish for the return of the empire. In a future drawn with the gentler hand you describe, I think that time would not have been funny at all; that would, historically speaking including in my own earlier reference to Versailles, in fact be just the sort of movement to prompt yet another Pacific war - which if prevented would only be so because if not occupied by the United States, Japan would have faced Soviet conquest (remember Tsushima!), which famously left no flowers of any kind intact within its reach: they would surely have had a constant and enormous problem with civilian "misbehavior," no doubt resulting in collective punishment, but would succeed in keeping the victim off the world stage.
The idea of Soviet occupation as preferable is heterodox to say the least, but I'm still also very confused as to what sort of terms you think could have been achieved by either Truman or Hirohito, in the absence of the demonstration strikes whose necessity you discount, when even in their aftermath there was a somewhat credible military coup attempt, the so-called "Kyūjō incident," with the aim of continuing the war. That attempt failed because attack orders, sent under the name of a murdered major general, were ignored. They did not have to be. And you don't seem more interested in considering Stalin's extremely compelling reasons to spoil any multilateral peace negotiations that might occur, and the again potentially war-starting impact of an attempt at unilateral negotiations which it is hard to imagine even (the admittedly somewhat bellicose in comparison with his predecessor) Truman seriously contemplating.
You say peace is the goal, and no one disagrees. The problem that remains is to explain how peace is a consequence of the course of action you would prefer had been taken. It isn't so much that I disagree with your historical analysis as that I am asking you to present it.