I agree with everyone that the legendaries have become far too many and of lower quality. Remember the excitement of catching Articuno after making your way through the caves? Remember the triumphant feeling of catching Moltres in Victory Road, on your way to everything you've worked for up until then, to beat the Elite 4? Remember the earth-shattering encounter with Mewtwo?
Their backstories were well-written; we understood and realized their rarity and the prestige of even running into them (meaning you've completed a milestone within the game!). Now it's just "OH, so now I need meet the mascot of the game", or "MOM! I need to go to NY to get Darkrai at some random Pokemon event!". Nintendo has ruined the fun in meeting and catching legendaries.
