Rejecting the existence of fundamental declarations hold as true (dogmas) is naive. We do not believe in them. Instead, they state what we believe in. This means that they are exactly what we must discuss.
The problem with fundamentalism is its broad understanding of what counts as fundamental. In a similar way, dogmatism, as a general way of thinking, considers any religious belief as a dogma. One and the other make a discussion not only undesirable, but also inconceivable. Here lies the threat that they pose.