Some questions for critics of pro/rel

One thing I noticed about critics of pro/rel is how confident that it would never work in the U.S. These are questions I have for them:

How do you know? Has it been tried here before? When and where?

For that matter, are there places in the world where pro/rel has been tried and it ended in system failure? I often hear these critics say that someday there will be collapse in these pyramids, but that someday never seems to get closer.

Do you think that there’s anything to the phrase, “you never know until you try?” Have you ever said it yourself?

Then what makes you so sure about pro/rel in the U.S.?

Are you 100% in your predictions of what will work and what won’t? If so, why aren’t you the richest person in the world?

Why not try it? I really don’t understand the vehement distaste folks have for it in a sport.