I most definitely do not subscribe to the point of view that suggests that God wants all his people to be rich, but Psalm 112, at first glance might be saying that this should be true. After all those who fear God and "find great delight in his commands" are blessed and "wealth and riches are in their houses".
While most of us probably wouldn't balk at the idea of facing the dangers and pitfalls of wealth, of which there are surely many, most of us will not get the chance to find out if it's difficult or not to remain generous and gracious, full of compassion and lending freely, conducting our affairs with justice.
The issue of personal wealth is not actually the heart of the message of Psalm 112. The Psalm goes on to talk about facing darkness, enemies and bad news. Perhaps the downside of wealth is that no matter how wealthy you are, you can't avoid bad news.
Whilst their houses might be full of riches, it is their righteousness that endures for ever. It is as the righteous that they will be remembered, not as the wealthy. What they do for the poor far outweighs what they might have done for themselves. I guess that's because our ability to be generous is predicated upon our experience of the generosity of God. If we have not experienced God's grace, if we fail to live in the shadow of that grace, then we are highly unlikely to extend that grace to others, especially if it is going to be personally costly to us.