But Reverb offers buyers plenty of protection, no?
It really depends. In the case of no ship then yes, in the case of the item being flawed then pretty much no in reality. They have recently changed their policy so that if you need to dispute the transaction they have first and last say on what happens, typically running the buyer and seller into each other repeatedly until a resolution Reverb can keep a cut of is agreed upon- usually to the dissatisfaction of the shorted party who just wanted to buy a fucking guitar. Before that folks' only recourse was disputing the transaction with their bank or PayPal while Reverb pulls their cute little bank/not-a-bank who is asleep at the wheel arbitration. Now if that is done they will breach the ToS and Reverb can tell them to go fuck their hat.
Most folks don't realize that buyer protection through your bank exists and can be very helpful. Reverb acting as a third party escrow really puts a target on their back between private parties when Reverb advertises, but doesn't actually render, protection services. That's why they changed the ToS. FWIW I've had better deals and sales through Guitar Center of all places, and they have no problems with untangling customer satisfaction IME. I've never gotten a good guitar off of Reverb in comparison.