This perspective under-appreciates the role of a leader's charisma when it comes to attracting staff that will actually execute the ideas of that leader.
Anyone who has worked in a presidential administration (or a congressional office) can tell you that a leader is effective if and only if they have staff that believes in their message and agenda, and that is willing and able to execute on that agenda.
The practical reality here is that charisma isn't just a way of gaming the "getting elected" part of the job, it's also a requirement to be effective at the job.
I think you didn't get to the part of how it would work in practice. It's not that the leader is selected randomly, it is that the people that select positions are randomly chosen. Also, your criticism only is valid if everyone through that being able to sell an idea is critical for the leader. The leader role is to manage the resources to accomplish the goal of the team, what the goal of the team is, is up to the team to decide.
Article suffers a bit from the common hackernews intellectual bias.