People already poited out that a) Sweden wasn't very poor in the first place b) didn't participate much in conflict during the time; and, most importantly c) technology was extremely influential in the sense that there was just more to go around.

I want to point out that I think (c) is by far the most important fact but that the post ignores; however, it also ignores lesser factors such as the widespread participation and effects of labor unions.

I see the post as grossly oversimplifying (by conveniently ignoring many other historical factors) while the last time I check, this is something that's still very much debated by modern economists.