The Golden Compass was recently remade into a TV series that was quite successful so think licensing might be a issue there. I don't know who owns the option for John Carter. The issue comes to the licensing. Not anyone can just remake a book adaption. Studios and production companies basically rent a licensing agreement and it is up to them whether they use it. Sometimes they can be locked away for years till they expire and either someone else buys it or they renew it and lock it away again or use it. It comes down to whether they prioritise making it or not. I suppose if a director comes to the owner of the agreement with a really could pitch perhaps they would let them make it.