@Calamity
It’s intended.
The more the stats are divided, the more overall points are given.
While the normal exotics have less overall stat points, they are more focused in a single area.
On the other hand, this amulet isn’t as focused on a single area, but it increases everything moderately to a further degree.
From a blog post for long ago:
“With our current implementation of the item system, items raise single attributes higher than when they raise a pair. However, the total number of points will be higher for a two-attribute item than for an item affecting a single attribute. For example, a Rare Ruby Ring gives +40 power; an equal level Gold Topaz Ring gives +33 power and +25 vitality; and a Pearl Ring gives +25 power, +25 vitality, and +25 toughness. This item system enhances another choice: do you max out one attribute or raise the total effectiveness of all your attributes? The character who deals the highest raw damage is someone who has maximized the offensive attributes, but the character who diversifies becomes a jack-of-all-trades while mastering none.”
http://www.arena.net/blog/pax-east-preview-izzy-on-attributes-and-iteration