Artists have been posting on FurAffinity to get commissions to earn a little extra cash since the site started, and the practice hardly started there. There's nothing wrong with it either: people pay, they draw. Earning money by doing work is an old and respected tradition.
A year ago, most of them were of the form, "I'm saving up for a Wii/PS3/tablet/other toy. Please commission me!" There were always a few emergencies, but most of them were by artists who wanted to earn some extra money to buy a luxury item.
These days, a typical plea is more like, "Please help! I got laid off and I'm $140 short on rent, please help me keep a roof over my head for another month!"