Believing democracy to be irrational is probably a result of mistaking it's purpose. We say democracy is the best system because it lets the wisdom of the crowd influence decisions and it moderates governments but it wasn't installed nor expanded for that reason. Charles didn't sit on his throne and think, "by golly, this ruling business is pretty hard, I better get some help" and the parliamentarians didn't get stumped centuries later and decide to see if women had any better ideas. People fought for suffrage for their class to advance it's position in society, to at least some degree of success in every case.