To be honest, I'm not that concerned if James Cameron and George Lucas took inspiration from the Carter books for their own films. It neither diminishes their films (and I enjoyed 'Star Wars' and 'Avatar' as films more than 'John Carter' anyway) nor elevates 'John Carter' because while the films themselves might all share similar story elements..................'John Carter' is still sadly a muddled and a less enjoyable film at the end of the day.
It really just means because 'John Carter' is coming up at the rear of the pack so long after Lucas (four decades too late in his case) and Cameron put out their films that everything in 'John Carter' feels tired, rehashed and at times forced. That's undeniably unfortunate for it from the sense that it told the story first. But it remains a fact the film can't overcome the way it's executed.
Andrew Stanton (making his live action debut after huge success with Pixar) clearly struggles to transition from one form to the other and the film's structure and plotting are messy to say the least. Add in a very underwhelming leading man in the form of Taylor Kitsch as the titular Carter himself and what you have here is in some ways a nearly $300 million dollar vanity project made by a director who can't keep it all together properly.
There are plusses to the film in as much as the world of Barsoom is beautifully well realised (even if some of the CGI effects maybe aren't quite as good as some are claiming, I have seen better including those in 'Avatar') and there's obviously a lot of additional story and events that could have been allowed to play out if the film had been less of a financial disaster. As it is, a franchise and continuation of the story seems very unlikely, alongside the chance to fix some of the serious problems in this film.
A bit of a shame, but that's how it goes sometimes.