Grinding and the Addiction Curve

Preamble:
Human behavior is built around the addiction curve; and one of the reasons many RPGs work so well is that the "reward" for grinding feeds this addiction. If the reward comes too quickly too often or too late too often, then the addiction weakens.

Question:
How do see the recent changes in this game weakening the affects of the addiction curve in your own play style?
or
Conversely, if you're seeing it strengthen, what game elements are contributing to this increased addiction?