I'm sure Canon doesn't see CHDK or the community that revolves around it as inconsequential. No hardware maker will see the community that hacks their products as inconsequential.
I am not sure on how Canon looks at CHDK, but I don't think they take this projects very seriously. It doesn't cost them any money, and most companies that offer end user products are rarely bothered by the modder community (unless if those modders do stuff like disabling copyright protection and stuff like that).
Still, it seems that Canon has chosen not to make an open move - either to encourage CHDK development or discourage it. I'm sure they are aware of CHDK and I'm sure they know ways in which they could help the efforts. If they're smart, they'd be regularly monitoring this forum and the wiki. If they already know all of this, I doubt a petition would make any difference in there policy regarding CHDK - whatever it is.
I don't really see a big company coming to a small group of developers and saying: "Hey, we like your work, how about we give you the SDK?"
But if their customers come to them in large numbers and say: "You know, that new camera model do not support CHDK because you guys made it hader for the CHDK developers to hack it, so we are instead going to buy an older model off Ebay, so that we can use CHDK with it", then they might be more willing to cooperate with the CHDK project.
It's ultimately about money, and if people vote with their wallet, then companies usually listen.
One case is the King Quest 9 game. A group of fans started working at this game, Vivendi Universal told them to stop, then a lot of people contacted Vivendi Universal, which eventually told them: "Ok, go head, make your game".
Another case is Compaq/HP sponsoring an effort to port Linuc to their PDAs. And there are many, many examples where big companies realized that working with their fans is actually a good idea.