That's an excellent point. The homebrew scene is often the one that does all the hard work and the pirates reap the rewards of the broken security systems (Notice how the security system of the PS3 wasn't broken until well after the Other OS feature was removed and the community wanted it back).
With Nintendo however, they've had a history of absolute control over their console and I think that it's been working against them in the long-run. In fact I remember a specific instance with the Wii where the homebrew scene had discovered a security flaw that was not necessary for homebrew but could be exploited by pirates and the folks who discovered it even attempted to contact Nintendo to let them know and to also extend an "olive branch" to them to let them know that the homebrew scene isn't trying to break the consoles for piracy's sake. Of course Nintendo gave them the cold shoulder and it was exploitable in the wild for a while until it was eventually caught by Nintendo's engineers and patched in a routine update. The only problem is that Nintendo's updates have sometimes been known to cause problems and it was ironically enough the homebrew scene that had the fix.
I'm not sure that the homebrew scene is quite that heroic, sadly. The DSi came out over a year ago and there is still no practical way to run your own code in DSi mode, giving access to the camera, extra RAM, internal storage, improved Wi-fi, etc. There is a hack [1] to run code in DSi mode, but this has already been fixed in newer DSi and XL models.
IMO the reason this has not been cracked wide open is that there are not enough DSi-only commercial games to make it worthwhile for the folks that create cartridges used mainly for unauthorized copying. Being able to copy and run DS-only games is enough.
With Nintendo however, they've had a history of absolute control over their console and I think that it's been working against them in the long-run. In fact I remember a specific instance with the Wii where the homebrew scene had discovered a security flaw that was not necessary for homebrew but could be exploited by pirates and the folks who discovered it even attempted to contact Nintendo to let them know and to also extend an "olive branch" to them to let them know that the homebrew scene isn't trying to break the consoles for piracy's sake. Of course Nintendo gave them the cold shoulder and it was exploitable in the wild for a while until it was eventually caught by Nintendo's engineers and patched in a routine update. The only problem is that Nintendo's updates have sometimes been known to cause problems and it was ironically enough the homebrew scene that had the fix.