So Much Luck IM SO HAPPY!

[Lord Windos]

"good bug" is the problem with your argument here... How do one define them? One could argue that all bug are good as they all offer exploitation and give sorta a Headstart, making it easier. Where then, would one draw the line? Exploitation and cheating/hacking aren't too far apart from one another, either, so what's to stop one from going too far and into cheating/hacking zone? You can't just ask for bug fix and hope the good bug will stay, it's like calling the exterminator and then ask them to not do their job because there are some good bugs in your house in addition to the bad ones...

I consider exploits thing that you can do to make the game easier/less challenge that hinge on bugs or using items/abilities in unintended ways. Cheating is when you use methods outside of the game proper to achieve the same effect. Of the two, I consider exploitation the less egregious crime, as you are still winning within the bounds of the game, and that exploits can be learned and master by just about anyone.
 
While you can argue that its better to fix all bugs, because its easier/more fair for both the devs and people playing the game, you could equally state that a bug can enhance the game, if it does not outright crash it. Dark Souls, for instance, had several duplication glitches that allowed people to quickly reach the set meta level, allowing faster access to new builds for PVP. While they did patch it eventually, the bug did little harm to the overall game, and might have actually enhanced the multiplayer aspect.

Good bugs can be like a couch having fluffier cushions on one side than the other. You can fix it, or you can enjoy the benefits of the defect.