SPIDER MAN! SPIDER MAN!

[Slothy]

You mention Venom being stronger, and having the same powers as Spidey. You mentioned his ability to avoid the spider sense. Carnage is stronger than both of them, with other interesting abilities. His ability to control others thoughts with tendrils from his symbiote, for example. He is also able to avoid spider sense. It's opinion, but I feel there's more potential in the character than you give credit for.

Carnage certainly does have all of those things (though let's be honest, some of the powers they've made up for him over the years are just plain silly), but the important part of what makes Venom the better Spidey villain is Eddie Brocks connection to Spider-Man. He has a reason to hate him because he feels he destroyed his career, and he not only wanted him to pay, but he slowly stalked and terrorized him for weeks, if not months before making his move. There's also the symbiotes connection to him if you want to go down the road of the symbiote wanting to bond with Peter but hating him for rejecting it, but portraying that in a movie may get a bit tricky.

The closest connection Carnage has to Peter Parker is that Cletus Kasady shared a cell with Eddie Brock and accidentally bonded with the Venom symbiotes offspring. Honestly, I don't feel that there's more potential there than I'm giving him credit for. Certainly he has the potential to be a very large physical threat to Spider-Man, but there's not much to him beyond that, even if they chose to go with something more along the lines of the Ultimate comics version of Carnage who is vastly different. The way I see it though, Carnage doesn't bring anything to the table that Venom didn't already, and there's a lot more to work with in terms of making Venom an interesting solo villain. And considering you can't even do Carnage without tackling Venom first, I wouldn't want to see them do Carnage in a movie since they'd essentially be re-treading ground they already covered, but which is much less fertile than before.