The KNVvL has already protested against closing the airspace for low-level VFR traffic. There is no good explanation for this, other than maybe some ass-covering.
Tim, the tulip fields in the "Bollenstreek" are in full bloom now. While you're stuck in Amsterdam, make the best of it. Either book a tour that departs from Amsterdam, or take the train to Leiden and rent a bicycle there. It's a beautiful day today and tomorrow with light winds so make the best of it!