Embedded in the press release is the real reason for it.
genuine passengers using Ryanair’s website have been suffering long processing times and slower access because of the huge volume of information being downloaded from our website by these screenscrapers all over Europe.
I had a problem getting my boarding card from the Ryanair a couple of weeks ago. It was very irritating. I would suspect FR is prepared to take the short term hit for the sake of keeping the website working faster.