I think people use pseudonym's because they're in danger of being "typed" as a particular kind of writer. People have expectations regarding books by a given author--infact, in most cases if they could be hypnotised they'd probably love to read the same book again. If you look at the prose style of someone like James Ellroy then I'd argue there's an individual who's taking the genre forward & not just cashing cheques. Someone who's willing to lose readers by altering their style is brave--why kill the goose that laid the golden egg?
that's true. Ellroy is such an original. but couldn't someone use a pseudonym because they don't want people to know they wrote in a certain genre. Like i often wonder how many writers may occasionally write in genres they'd be less than thrilled to have people know they wrote in!
There's yet another reason for using a nom du ordinateur. I am also a travel writer, and at one time was so prolific (he said modestly), magazines were using three of my stories in the one edition. So I had to use two pseudonyms. One of them stuck, and I still also write under that name as well as my own.
As far as Brady is concerned, she is totally right to sue if she was affected by fumes. However, as far as I can remember, she did state in court that the effects of the fumes stopped her working on her literary novel, but not her thriller. There is a clear implication there, in my mind.