It can be very hard to get paid for writing fan fiction. <grin>The point that what fans want from fanfiction they don't want from canon is a good one, especially if you've ever seen fandom arguments that 'I don't like how this has gone, if only the canon had been like [popular fanfic]'. Which is a big lie and just another way of being disgruntled about a character development.
EDIT: The other thing this article leaves me with is the thought "there's a market there! I should try and learn to write this stuff"