The implicit idea is that any improvement in beliefs is beneficial, but it's not what comes to mind when reading that section, it sounds as if suggesting that there is this special kind of beliefs whose revision would be beneficial, as opposed to other kinds of beliefs (this got me confused for a minute). So the actual idea is to focus on belief revisions with high value of information. This is good, but probably needs to be made more explicit and distanced a bit from the examples representative of a different idea (inconvenient beliefs that you would like to go away).