I believe most people already blamed the Players.
I for one blame most players on the marketboard, for what I consider, foolish selling practices.
mostly undercutting In singles, rather than in bulk.<I have sold so many stacks of items by selling them in 2-4 stacks at a higher price netting me money off the undercutters. and I only bought their stacks in the first place cause I needed the item to craft something.., whilst lowering other players overall GIL costs to advance>
But that's just my view.[and I probably haven't run into the threads or posts where people are blaming the Devs/SE/CBUIII]

(But I have seen people get mad at the devs for the latest store change, which is reasonable to assume is only temporary, whilst they deal with RMT)