Based on the figures shown via the Questions and Users links, it seems that there are 2,575 questions, and 4,652 users.

I head Joel Spolsky (co-founder of Stack Overflow) talking about how, in general, people prefer(?) to answer questions than to ask them.

I would think that it's because; the more you know, the less you need to know (of what can be gleaned from a single point-specific question/answer).

However, an average of 0.55 questions per user surprises me.

Are the totals correct?

Update:

I just checked the other stack.. sites I use:

                    Questions    Users   Ratio.  

unix.stackexchange:       934    2,412   0.39
askubuntu:              2,575    4,652   0.55
superuser:             55,160   48,893   1.12
stackoverflow:      1,004,367  372,605   2.69

A low ratio seems to be just a reflection of the newness of a site (assuming a site "takes off")... so by seeing more stats, I'm now not surprised any more. It makes sense...