Unfortunately, for my point of understanding what journals do provide this is unhelpful, as salaries could still be spent on useful things.
I belive that blog posts like this focus on the wrong part to be convincing: What do journals provide and why do they have expenses that are this high? If we ran journals as non profits, should we expect cost to come down by the 27-39% (for the three publishers chosen in the blog post)?
If they want to be convincing for me, I believe they should focus on those remaining 61-73%, and why I, as a reader, should believe a different organization would reduce that in a meaningful way and how that should be financed. Making researchers do even more of the jounral busywork is a bad solution as well, even though it provides implicit financing, as it wastes even more time of researchers.
Not that I actually need convincing that an open knowledge model is better, I just prefer hearing good arguments on my side instead of infinite repeating of bad ones.
I don't know much about accounting, but as far as I know, dividends are not expenses in any way and therefore are part of the profit margin, not the remaining 60%.
Salaries.