Afghanistan is already a full member and therefore they should strive to enter the semi-finals. For a team like Netherlands (being an associate member) it will be great news just to defeat 2-3 full members. But that is not the case with Afghanistan. If they can't enter the semi-final stage this time as well, then questions will be raised about their test status (similar to the ones that are being raised for full members who failed to qualify this time - West Indies, Ireland and Zimbabwe). Defeating Netherlands today should move them close to a semi-final slot, but two more tough matches await them in group phase.
I think it's early to expect such things from Afghanistan, they have already done justice with there performance. They have won 3 games and looks like wining another game today. This WC is confined around 4 teams aka Aus, NZ, SA and India there is hardly anything left for others. This World Cup is a nightmare for SL as they have faced huge defeats this time.