In the way you are saying the Eldar are good and balanced, you might as well say no more Marine players can use anything but Codex Space Marines. Sure, lots of options, broad range of selection, traits to tinker with.. But that does not sum up Marines as a whole, which is why they would release a codex per major chapter. Try telling every BA and DA player that codex Space Marines is fine for them and they aren't getting nerfed; you will hear alot of complaining and disagreement there too.
The over-powered bits of craftworld eldar is the development teams responsibility to fix, not totally remove. I want to see multi-farseer Ulthwe with seer councils. I want to see Court of the Young Kings. I want to see some sort of Disruption table. I want to see some specific Wild Rider options, even Iyanden-specific traits.
You might say, Hey! Codex Space Marine is the same. Wrong. That trait system is still a big leap in customizing your chapter, by giving it powers and restrictions. Eldar might have intermittent little powers, but nothing of that nature. It is a balanced codex, is does give larger assortment than 3rd editions meager list, but it failed huge where it was supposed to have a spot for craftworlds, nerfing every eldar player that used one, which is nearly every single one.
I'll agree, it's a good codex, sure. Has some great rules in there and beneficial changes for the Eldar, yeah. But that isn't the point. The point is that is did very much nerf every eldar player except the super-just-started newbs who didn't know much about craftworlds.
I enjoy the codex and will use it to get as close to my old Biel-Tan as possible, but it won't be the same. You might say taking aspect as troops is overpowerful, but it leaves me generally wide open for heavy gunfire as they are as expensive if not more than marines, especially after upgrades. The benefits of the craftworld lists were their downfalls, as people wanted to blow all their points on powerful units. Deathwing, Ravenwing, these aren't s different. Nerfed, I say.