Yes, I think a critical mass is being/has been reached, since the roll-out of the Partner Programme, which gives so many millions more people worldwide the incentive to try to game/flood the system.

Medium either (a) failed to anticipate this, or (b) failed to plan effective defences. Or (c) just figured that 'Hey, five bucks is five bucks. Never mind the quality - feel the width!'

I think the smart money's on (c).