There is nothing to attach, nothing to hunt for at the back of the neck. A hinged piece builds the opening mechanism into its own structure, which means the person you're giving it to interacts with one object, not two.
The Perfect Fit
Hand diameter is the variable that matters most when gifting a bangle bracelet to ensure it fits. If it's too small the bangle won't pass over the hand, but if it's too large, it will rotate and shift up the forearm during wear.
Visually Speaking
A lobster clasp projects and rotates. A box clasp is flat, rectangular, and sits at the same plane as the piece. On strand jewelry and flat-link bracelets where the closure is visible, the box clasp maintains visual flow in a way the lobster clasp physically cannot.