Lord Housewife, your OP would be vastly improved if you gave some examples to support your thesis, rather than just stating your thesis and assuming its truth, and then spending the latter 3/4 of the post saying...well, nothing interesting.
Let's take Riot's S3 itemization changes as an example. How, in your opinion, did they make changes that strengthened that which was already good, as opposed to strengthening champs that were not good before the patch?
Because I look at Black Cleaver and see a rejuvenation of overlooked champs like Talon, Pantheon, Urgot, and MF (to be fair, this comes along with champs like Riven, Renekton, and Lee Sin who were strong before the change). I look at Runaan's Hurricane and see love for previously maligned ranged champs with heavy onhit aspects, like Varus and Twitch. I also see changes to Wit's End, Phage, Trinity Force, and Ionic Spark (to Statikk Shiv, basically) as penalizing previously strong champs like Jax, Irelia, Ezreal, and Shen.
So does Riot really make item changes to strengthen that which is already strong? Does your thesis hold in the face of recent evidence?