Chronicles was advertised as being a game that would explain various mysteries of the Sonic lore, so it's still important and the characterisation should have been miles better. And while it may be licensed, it still uses the game universe (like Sonic X).
And how is Sonic being an *** "character development"? If anything, it's regression and flanderisation. Simplifying his character to revolve around a specific trait, ignoring all of the lessons and wisdom he's picked up over the course of his adventures. Sonic isn't supposed to be a one-note character, he's supposed to have more layers to him than "he's an ***".
They don't ignore his other traits anyway. Him being an ass is just a unique personality compared to his snarker, which is still overall there too. He's pretty boring when he isn't an ass at first, and they barely develop him at all. He's the blandest of the main characters overall, sadly. The rest either had more unique personalities from the start(Rouge, Tails) or gained quite a bit(Amy, Shadow as of his game). Overall, I'd say the other universes made him more memorable than "simple heroic personality". I mean, he's still less bland than Mario, who has barely a personality(bar the spin-offs, like Comics, etc.).
Also, he develops from being an ass to a better person... although not often. Sadly this only happened in Underground, but character development was a bigger focus. No idea why they couldn't develop him during SATAM when it had a proper continuity. Sonic X kind of does, but he's his game personality anyway. Impossible to properly do in Adventures and Boom due to lack of proper continuity, however. Do note that I'm not referring to the games.
Chronicles is still pretty much its own thing overall, and they did clearly intend to add it into the game canon, but it never became canon however. Which is probably due to it having completely unique characterizations, and likely trying to bring the Comic stuff in. Sega overall saying "nope" to that is understandable, never mind other possible copyright issues with the storyline. At least, that's from what I understand on why it isn't canon.