If you haven't yet, what are you waiting for to go watch "John Carter"? Grab your kids, grab your boyfriend or girlfriend, your spouse, your parents, your friends and run to the nearest theatre where they're showing this. For you can watch "John Carter" being any age, and in any company, and have a good two-hour cinematic joyride.
It doesn't matter that it has reportedly failed at the box office (but then, failure is relative, isn't it? It all depends on how high the expectancies were raised). "John Carter" is a great movie, and I hope it will have a fruitful second life upon DVD release and in other forms. It doesn't matter that Mars doesn't hold almost any interest for human fantasy anymore as it did back in Edgar Rice Burroughs's time. It doesn't matter that the plot isn't perfect and that the movie sometimes reminds us a little too much of "Avatar", what with the interspecies romance, the seemingly hostile environment and creatures then turned into allies (or not!), the ecologic, Earth-loving message. It has lots of adventure, love, humor, and enough symbolism to get the point in just one viewing and walk out of the theatre with a smile in your face. The characters -the good guys and gals, that is- are all good-looking, well-spoken, brave, smart and funny. And the bad guys also make a good point in the story -perhaps the most intriguing, most modern message of them all. And the cast is really gold, especially the more minor characters (it has Dominic West, by God!).
In summary, please, do yourself a favor and watch "John Carter". At worst, you won't find it anything special, but I trust you won't be bored.