you wrote: "I know more about how the Spybot Team operates and tend to trust their list more anyway". --- there's nothing like having "inside information"
you also wrote: "I believe this issue is really insignificant". Agreed. But most users don't want to have to choose (nor do most have sufficient knowledge to properly choose) between these programs. Each has its advocates. And since, with few/minor exceptions such as the one we're discussing here, they can "peacefully" coexist together, I think many people will continue to combine both, on the basis that doing so will "maximize" their (passive) IE protection. [of course, this reasoning does not apply to IE8, which has an issue with "large" collections of restricted sites.]