I think you'll find that the quality of PX maintenance has not decreased significantly on the hangar floor but the priorities have changed. During 2004 / 2005 when a clear operating profit was declared; the technical spares calculations and provisioning and the component overhaul contracts were driven and maintained by engineering; and overall despatch reliability increased as a result.
Since the 2006 management changes (particularly at the executive level), PX engineering and supply departments are now micro-managed by accountants who have little aviation based experience or background and who base their priorities on parameters that are not operationally logical but sound good in the boardroom.