[quote=So Boerd]Of all the disputations to have, that one has the least impact.[/quote]

Impact in terms of Religious Wars or Crusades perhaps.
But it has a rather big impact on education and scientific knowledge.

[quote=So Boerd]What difference does it make if they don't?[/quote]

Quite a lot, it's basically going "What difference does it make if we believe in Gravity, but say it doesn't apply to humans?".