Because the element node is not tied to the restraint for the moments. So whatever moment is, it is not transferred outside here. it is transferred to the next element. This is a simplistic representation. In fact is more complex.
Because the moments and forces are not disappearing in the air, you need to find somewhere else this moment. In your case part of it will shows up in the opposite forces in the two first guides. part will be absorbed by the flexibility of the elements.