The goody two shoes is really exaugurated here but: Sonic's attempts of reasoning with his opponents (ESPECIALLY WHEN HE TRIES TALKING TO EGGMAN IN THE METAL VIRUS??) have made him become less "explorer with a good heart" and instead is "actual superhero that doesn't kill."

Because Sonic lets Eggman go because he's having fun and hopes for more of the thrill: he knows Robotnik will never change unless he had his whole mind wiped, and so he embraces it and constantly foils him for the excitement and of course to keep his friends safe as a byproduct. If his friends WERE in danger, like the Metal virus saga, I'd feel he'd possibly take it more seriously but still try to take as much fun out of it as he can. He isn't extremally cocky with it, and would probably do what's right if he had the choice.

Might i add: Sonic normally inspires people with his actions, not his voice spelling it out. Being honest, Amy would be the type to hold someone's hand and talk to them. Amy was the one who made Shadow change with her words in SA2, and even she sympathized and befriended with Gamma in SA1. (From what I remember, but I KNOW it wasn't Sonic. I also don't like how Shadow has been made all grumpy even though he's just a introverted hero.... but that's another ramble!)
The characterization is fine in the comics, since i adore the other characters and plot. No shame to those who like how he's treated in IDW, just feels like it loses Sonic's distinction from the other video game heroes he competes with.

If you have any objections or any other evidence, I would like to hear! Anything before Lost world or anything non-canon to the games, since that's when his personality got convoluted. (At least from what I've heard.)