Actually, that's not the case. Though it rarely EVER comes up in today's gearing, Blizzard has an item level weight system. The net effect is, you always want an item to have as many stats on it as possible. In the old days, many items had 1,2,3 stats on them. But an item with 4 or 5 or even 6 was always much better, for that reason. When Blizzard wants to "overitemize" an item, they'll do exactly this even now, such as the rogue legendary daggers.
In any event, an item level 600 cloak is HUGE.
And, I think, we are seeing the REAL reason behind the item level normalization. Blizzard has been "held back" by pvp in pve for quite awhile. They can't deliver super powerful or interesting pve items if they will be used to destabilize competitive pvp. At the same time, they want to use the same general formula for pvp gear over and over again, so that class performance stays intuitive. With the upcoming patch, Blizzard is doing the following:
1)- World PvP is thrown under a bus. This has never been balanced, and they are going to dramatically crazify it, with item level 600 cloaks, legendary weapons for all raiders, insane trinkets, etc. The "carrot" for having the best world pvp stuff is going to switch from arena/RBG to heroic raids (and reg mode raids), which is very likely intentional- getting really amazing pve gear is MUCH HARDER than getting really amazing pvp gear- and you can't even WEAR it outside a damned raid. You can be questing around in full raid gear on live, and if you get caught in a shockwave you're just fucking DONE without resilience- raid gear currently feels like "pve instance only" gear. Normally, the only "hard" gear to get in pvp is rating based, which is gone now. This is not to say that a pve player is much better than a pvp player, or any garbage like that- merely that the gear in pve is a huge part of the gated reward, but in pvp it cannot be, or the guy who is on top will be super dominant. If I do double the dps of a rogue in less gear, that doesn't break anything. If I gib everyone in a cheap shot, that does.
2)- Arenas and Battlegrounds will be, for the first time in WoW history, free of dragonslayer loot. Walk in with that item level 600 cloak to arena? Oh look, it's 496, with a small advantage in secondary stats which will in NO way compare to the pvp power on the conquest cloak (and in fairness, it is probably worse than the 476 honor gear). It'll have the same mainstat and stamina. PvP gear becomes CLEARLY dominant in all manner of rated and even unrated instanced pvp. Anywhere you queue for, everyone will be in gear that looks like this:
Poor gear- questing shit
Ok gear- 496 raid gear (ANY raid gear that gets downsized to it)
Ok-Good gear- 476 pvp gear with enhanced stats
Strong gear- 483 or 491 stuff from last season
Real gear- 496 conquest gear