I am hard pressed to see Athens from a few thousand years ago as a real case study, its simply to far out of our frame of reference. Switzerland in more recent history is a rather ugly counterexample to your theory. They had a referendum on women suffrage in 1959 which was declined by a 2 to 1 ratio. You assume a well meaning population, which doesnt have to be the case. Direct democracy is still the dictatorship of the majority over the minority. There is just the hope to have better chances on get the equivalent of a benevolent dictator instead of mad tyrants. And if that fails we put our hope in the bdfl in form of the constitution.
But back to the point i dont think you can compare business with societal structures. We are not doing democracy because its more efficient. Its extra effort we spend in hopes to achieve a better society. People have an entirely different stake in their job as in society. For your job the hassle is likely not worth the trade off (if there are any for an employee).
And back to OP
>A lot of people who advocate flat or structureless organizations actually have philosophical problems with even direct democracy for decision making.
I have to agree with the statement. The "real" democracy as a solution to the problem of organizations falls short. Crimethinc had an interesting article on the topic (which got turned into a book later) https://crimethinc.com/2016/04/29/feature-from-democracy-to-... . Its their usual over the top approach but an interesting line of thought.
Although, you lost me here
>Smaller objections to things like elected positions and parliamentary procedure, which are seen as too hierarchical.
I wouldnt say proponents of non hierarchical forms of organization have less of a problem with the representative approach.
