User blog comment:Jimeee/Skyrim 1.9 beta update adds Legendary difficulty and raises level cap (Updated Apr 8th)/@comment-5959778-20130330150319/@comment-66.102.73.11-20130330162013

Because they are interested in preserving the games integrity, and ensuring that people don't just attain legendary perk trees only to refill them in an instant. The Oghma Imfinium glitch has been patched several times, and generally there are always work-arounds found by players, so I wouldn't get worked up over it just yet.