Up until now, the only problem with them has been the clumsy punctuation we use. If we use a traditional question mark, some yahoo might answer. If we use a period, we sound like Eeyore, the donkey who needs Prozac.
So thank you, Craig Conley, for this, the rhetorical question symbol. Why didn't we think of that? (Wait, don't answer -- it was rhetorical.)
See more of Craig's mad genius here: http://www.oneletterwords.com/weblog/