You can protect the title of your book, it's just that most authors don't.

You might be able to trademark it, if it's sufficiently unique in its market to be trademarked. (i.e. you form a corporation with the book title as its slogan, or you attach the trademark to some product or service you sell.)

However, contrary to popular belief, trademarks do not prohibit others using your trademarks in their writing. They prohibit others using your trademarks deceptively or in a way likely to cause confusion. Which means you don't have the same ability to prevent someone from using your trademark in the title or content of their book, that you have to prevent them from using copyrighted material in their book.

Exactly. There is no protection to the title of books. The reason the author can force to change the title is the same reason you can be "forced" to sign an EULA. If you want to use the story, that is illegal until the writer contractually gives you that right. He can put whatever terms in that contract and you can say yes or no.

So an author can force a film company to switch all it's employees to rainbow colored forks in their family homes and the film company has two options : comply, or find another book to make a movie from.

This is similar to an EULA. You are in no way forced to sign the EULA. But there's nothing else giving you the right to use the software. So you have one of two choices : agree to the EULA, or find another piece of software.