One of the issues is that OCS has a monopoly on PRM assistance
EU1107/2006 removed the responsibility of PRM provision from airlines individually - who used to be able to contract with any of a range of competing suppliers - and handed that responsibility to airports, who by and large have contracted with a single supplier for their entire PRM requirements, the costs of which are then met by a PRM levy on every passenger's ticket. All of the airports assessed in this year's CAA report have a monopoly provider for PRM assistance so it's a level playing field - and one backed by EU regs - in that respect. I think there are a couple of airports where the operator provides the service with its own staff, but for the mostpart, it is contracted out to third parties who are then managed (or not) by the airport operator.
Having flown through MAN T3, EMA and STN all in the last month, there is a common theme through all three of a total lack of customer service. For balance, I've also flown through GLA, EDI, LHR, LGW too, all of which have been far better. I find the MAG airports to be poor in comparison. Security queues at all three are routinely longer than anywhere else; they are still paying people to shout at you for daring to look at your mobile phone when in the lengthy queue; there is a lack of airside seating particularly in MAN T3 and even basics like cleaning and toilet checks are poor - EMA this week was a disgrace. I don't know if they have someone in MAG responsible group-wide for security and customer services, but if they have, the individual needs to be replaced by someone competent. Other airports are managing infrastructure and big construction projects well, alongside delivering a customer experience on a day-to-day basis. Grand though MAG's future plans are - and I'm sure they will improve things - there are still several million passengers going through their airports in the meantime for whom the experiences are pretty grim. I'm not surprised they're bottom of every league table going - it reflects the customer reality of all three airports today.