It mostly have relation to we being able to access Protection, Resistance, and other stats that were only acessible on epic levels by heroic. Resistance +6 was a rare thing and well-sought. Now you can find ML 11 cloaks with it. This kinda shadows old items with proper numbers, like the
Stormsinger Cloak.
Sure, this specific cloak still is worth wearing if you are a bard because of being one of the few items with Anthem on it. But you are not equiping it for the resistance bonus. You probably will have resistance in another slot.
The same can be said for
most epic items with resistance +6 or +7. By epic levels you can easily find +8 or +9 to equip before 28, and make the full jump to +10 or +11 at level 28.
You can make the same paralel with items with seeker, sneak attack damage/deception, fortification, etc.
Dream's Visor is a unique example in the same vein of the Nightmare enchantment becoming acessible by random loot. It used to be a unique enchantment, and turning it into a general enchantment made the named item lose value by proxy. Think like if you made Madstone Rage or Transform Kinect Energy into the random loot tables, the raid items with those properties will instantly lose all their value.