It's all about the liability. Ran into the same thing when trying to rent out desks (coworking). Since we're an intermediary we can't bare the full responsibility: the actual things we rent out are outside our control. We were denied because of that. Luckily most consumers here in The Netherlands don't have credit cards, so not having CC checkout is not a big deal, and businesses are accustomed to paying invoices within x number of days. The number of invoices that get defaulted on is worth the risk.