I SR'd for Mewtwo and a few hours saw me get a great spread.And I really hate being told what I have and haven't done.You obviously never SR'd for Zapdos. And in ORAS it's going to be even worse because we need to do the entire selection process for a lot of legendaries (since according to Game Freak every pokemon is obtainable with XY and ORAS). That's going to take forever.
You can't say how this will work yet. But it's than before when getting good Pokemon = learning to RNG.