Not sure why you're being downvoted, this is widely accepted that both the bomb and the soviet invasion had equivalent weight in their surrender, with some historians saying the soviet declaration of war was more important.
To add on that, at the time of the surrender, the long term effect of the bomb was not known to the japanese and as such the nuclear bombing wasn't the worst city bombing they suffered, neither in terms of infrastructure damage or loss of life.
The "5 year old" comment probably has something to do with it. HN doesn't tend to downvote people into the gray just because they are saying something that other people disagree with, unless the comment is also not particularly civil.
I say things that many people disagree with all the time on HN, but pretty much the only times that I am downvoted into the gray are when I am not civil. For instance, the only comment of mine that has been grayed in this discussion is this one: https://news.ycombinator.com/item?id=9169426 That comment is little more than a personal attack, and was therefore downvoted.
> this is widely accepted that both the bomb and the soviet invasion had equivalent weight in their surrender
I seem to recall that from the archived discussions between the officials at power at the time, the Russian invasion wa the key topic at hand to capitulate before any soviet forces landed.
To add on that, at the time of the surrender, the long term effect of the bomb was not known to the japanese and as such the nuclear bombing wasn't the worst city bombing they suffered, neither in terms of infrastructure damage or loss of life.
Some more information for those interested
http://www.reddit.com/r/AskHistorians/comments/u6qqo/there_h...
http://www.reddit.com/r/AskHistorians/comments/2y98yc/did_th...