Why is there a distinction between full fright flights and other flights for the slot violation policy?

In the assessment of a possible justification all circumstances of the of the slot violation are taken into account.  Including all reasonable measures that can be taken by the airline. The rotation that an airline flies has an influence on the possible reasonable measures for an airline. An airline that has a short haul hub-and-spoke network have different possibilities for reasonable measures than an airline that flies long haul point-to-point.