Since when does a publisher tell a writer what is to happen in a book they're writing. I could see it if you said George Lucas was the one who told Denning to kill Anakin, but not Del Rey, who only publishes the books.
The only logical explanation for Del Rey wanting to kill off Anakin is as a way to begin to kill of the Star Wars Universe, one(or more) major character(s) at a time. But I've still never heard of a publisher telling an author what to put into his book.
If you can show me proof of your claim I'll be glad to take a look, but til then, sorry, I don't buy your explanation. And I STILL will not buy Star Wars books again until they bring Anakin back.
Call it a temper tantrum that won't hurt anyone but myself if you wish, but Anakin was the natural choice for successor to Luke Skywalker. He definitely had more on the ball than Jacen, not to mention the budding romance between him and Tahiri.
Besides that, I liked Anakin because he's so much like me in so many ways.