Trolleys and charges
I think we have to consider this in the context of what is happening in the air transport industry as a whole. In charging for trolleys MAN is only following a trend towards transparency of charging - you pay for what you use, and if you don't use it you don't pay for it. That - we are told - is what the customer wants. It is certainly the way the lo-co airlines work - with increasingly complex schedules of charges for what we once assumed to be included in the fare.
MAN was carpeted by some critics for years because it didn't run with the lo-co trend, but now I guess something like 50% of MAN's traffic is loco. Lo-cos and their passengers want cheap charges / fares, but the cost of running an airport doesn't come down accordingly. A runway / taxiway / ATCO / Fire Service costs the same whether they are being used by Lufthansa, or Ryanair. To be able to offer the sort of basic charging scale 'demanded' by today's customer, airports will have to look at where they can claw back some revenues through selective charging for 'extras' like trolleys. In the end it is the customer who has chosen this trend, or has been led to expect that air travel really can be cheap (I don't think it can be sustained). We can go back to high charges which cover everything, but will the travelling public be ready to pay the corresponding fares? Take your choice.