YES! I completely agree that the seller should have the ability to accept or deny an order.
I’ve been on Fiverr for over 3 years now and have recently “gone on vacation” while I contemplate leaving the site for this very reason. Recently, the number of bad buyers has skyrocketed. They know that once they place the order, you’re basically at their mercy as a seller and that if you don’t do whatever unreasonable request they ask of you, they simply leave negative feedback and kill your gig.
It’s a horrible system. As a seller, we should have the option to accept or deny work to avoid doing business with people that have been unreasonable in the past or that have bad buyer reviews. It would help sellers better manage their workflow and have more control over their Fiverr business.