Reverse the question. Now ask for a show of hands. Is a super majority still required?
Consider a group that has fallen onto hard times. Someone moves to dissolve the organization. After much discussion a vote is taken. 51% vote to dissolve. Motion fails. We must continue.
Now someone else moves to continue operating. Much discussion. A vote. That motion also fails for lack of a super majority. What now? No one wins, status quo rules, but status quo has been defeated.
I suppose the "continue operating" question is out of order. Maybe you are not supposed to reverse that question, but it still demonstrates how a super-majority system assures that the status quo is protected. The bias built into the system is that you must continue to do whatever you are currently doing. Why bias the decision toward a minority that wants to preserve the status quo.
Likely in a situation such as the above, people will leave the organization if they possibly can and while they can. I've been part of an organization that ran on consensus, had a intentionally weak organizational structure and ended up being taken over by members wielding lead pipes when things did not go their way. Those driven out regrouped and started a new organization while those who took over ran the organization, and its considerable assets, into the ground.
I've once heard democracy described as controlled civil war. We make a contract in which we accept that we will sometimes win and sometimes lose. The minority on a given matter peacefully yields, but the individuals involved may be in the majority on some other matter. But importantly, and often missing in our assessment of how things work, the majority must show restraint. If a minority feels too oppressed, they stop peacefully yielding. They leave the group if they can or stop cooperating.
A super majority might be appropriate where there is a concious and well-agreed intent to protect the status quo. You commonly want to discourage constitutional (bylaw) changes. But building a bias toward the status quo into every question will result in an unresponsive organization.