Not entirely the case, as I believe a lot of the bags are rush bags (ie unaccompanied, hence them being unclaimed) being sent from other airports, most likely caused by misconnects at hubs. The sheer volume of them appears to be too much for the handling agents to cope with. Yes they should be getting managed better at EDI, but they are unlikely to have bargained on hundreds of rush bags being sent in each day because the airlines are failing to manage their hub connections better. Just another sign of the disruption industry wide currently, I would wager a lot are off the US flights.