You're correct, my mistakes. The EU261 resolution found that airlines should pay passengers compensation in cases of “force majeure”. Aside from being as nonsense as taxing passengers to fund compensation cases, it left airlines with the choice of paying such compensation cases out of their own revenue or passing the cost onto passengers in the form of a levy.
So granted, Ryanair are probably profiting from the levy, but it was still forced on them by the EU261 resolution.