Right, the unmodified MIT license is fine. There haven't been any cases precisely because of how unambiguous it is in giving permission.
The question is, how do I know that a contributor to software under the JSLint license (perhaps a corporation that paid an employee to contribute something) won't sue me on the grounds that I'm doing evil with their code?
That is the context from which I'm speaking, where enforcing openness through legal means is not a concern as the license is permissive (I imagine you were thinking of protecting GPL software, which is kind of the opposite situation). There have been zero court cases involving legal dispute over MIT licensed software.