I agree with UKlad that lowering landing charges for airlines or cutting already cheap car parking could bring more pax into MME but the £6 PDF is guaranteed income whereas the other options are speculative and I guess the airport management are sick of looking at potential income and/or passenger figs and are dealing in the here and now.
As for Ryanair, I wouldn't worry too much as I strongly suspect that they will pull the ALC route anyway next year with or without the charge.
As UKlad said and like the comments in the local press from pax at MME on Friday, it probably won't put off those pax already using the airport who enjoy it being on the door step and see a sense of local pride in using it. Sure they'll be the odd few who spit their dummies out and use NCL and LBA but good luck to them as I for one don't enjoy being stuck by the metrocentre or dawdling along hte A59 for 30mins after having left the A1.
The stupid thing is, when you factor in petrol, journey time and parking, using either of these is going to easily quadruple the £6 PDF. I would guess a lot of MME pax save on parking and either get a taxi or family or friends drop them off.
It is make or break time for MME, although it saddens me to see the way things are going, I think its about time the people of Teesside stand up to be counted and show some loyalty to what is their airport. I;ve said it before but what would it cost for the local press to run a 'save our airport' campaign highlighting destinations and doing price breakdowns comparing the associated costs to travelling from NCL or LBA. For example, a lot of the time, KLM via AMS to CDG or other european destinations works out the same as going easyjet or jet2 once you add on the petrol money and car parking at the 'big two'.