Before people start saying it's another case of Ryanair throwing the toys out of the pram, you have to remember that the difference between a profitable and unprofitable route in Ryanair is maybe only a few euro. Therefore throw a travel tax in to the mix and for the company it becomes more and more difficult to fill the thinner routes as these tend to attract price sensitive customers. Price sensitive customers will see and 8 euro increase in fare as just too much to deal with, so best option for FR is up and move capacity else where ie. Spain. Look at the success Spain has had. BCN airport is growing (and its mainly down to FR) and so are the Canaries.
Once Ryanair begin to attract customers who are willing to pay a slightly higher price, they cant afford to take these hits in tax increases. Whats the point, at the end of the day they are a business.