@Kiozo, you mention being at your "peak" in gen4, and continue to compare gen 6 to gen 4. I don't understand why you're doing this, because the entire game has changed since then,,,
Wifi was implemented into the game by GameFreak because the total amount of pokemon that can be used by players continues to increase vastly, meaning you can't prepare for threats as well. For example, I can prepare for talonflame by using a Rotom-W, however because there are so many new pokemon being created and so many different sets used that I wouldn't be able to rely on Rotom-W to counter Talonflame if no-preview was still a part of the actual game - if I need to use rotom for something else, for example Belly Drum Azumarill will be able to weaken rotom Rotom, then bam Talonflame revealed and you're screwed...
tl;dr gen 4 =/= gen 6, stop comparing, the game has changed,,,