The movie is better than the take, yes (Taylor Kitsch is also a better actor than he appears to be in it), but the fundamental problem with John Carter is that the books don't have anything "special" about them, beyond their status as a historical artefact, and being somewhat influential. Also the audience that grew up reading them is now, um, a little past it and was never huge.
Partly this is because they've been influential re: steampunk-y depictions of Mars. I think someone mentioned this re: some of Moorcock's works, where they've been influential enough that some of them would also seem pretty "expected" or not terribly exciting - Von Bek would probably read like a Warhammer Fantasy fan novel, even though the opposite it true (Elric you could certainly still do).
Carter himself is also not as interesting a lead as say, Frodo or even Conan. He's a pretty straight-down-the-line male lead, and we still don't have a shortage of straightforward male leads (c.f. Netflix/Prime movies being churned out by the dozen). He doesn't have a strong ensemble cast to rely on. Sure the titular princess is considerably more interesting than him but she's not got the role that she might have.
So what are you left with? A fairly straightforward Isekai with a boring central character? Cut-rate Avatar? I mean, would there be Avatar without John Carter? Maybe, maybe not, but that shows more like what it would need to be to cut it today.