oh right, it's not like he can hold planets together on a whim or say thunderclap away dimension destroying blasts or exert infinite force when tested by The Leader.
the only thing the anger does is make it more difficult for Banner to hold back, it doesn't increase his strength it decreases his resolve.
WWH could tap into that at any moment, he just wouldn't because it was too much power, it would spill out and cause too much damage.