Yet that is what we see in Ecclesiastes 7:1-4,
"A good name is better than precious ointment; and the day of death than the day of one's birth. It is better to go to the house of mourning, than to go to the house of feasting: for that is the end of all men; and the living will lay it to his heart. Sorrow is better than laughter: for by the sadness of the countenance the heart is made better. The heart of the wise is in the house of mourning; but the heart of fools is in the house of mirth."
Now of course, the rationale for sorrow being beneficial is along the lines of James 1, in that suffering make the countenance of the heart better.
But I believe this illustrates (though doesn't prove) that contentment and joy does not imply that one is happy all the time. It is entirely acceptable to shed some tears now and then. One does not need to be an emotionless robot (or stoic) to find contentment in his circumstances.
Contentment acknowledges that the situation is undesirable but trusts God to give fulfillment in the situation anyway. It does not ignore hardship in the name of contentment.