"The above copyright notice and this permission notice shall be included in all COPIES OR SUBSTANTIAL PORTIONS of the Software."
Reusing a snippet doesn't require reproducing the MIT license. People who publish MIT software know they're basically giving their code out with basically no strings attached.
However, GitHub should be careful with the GPL variety.
This does not relieve the person using the code of the responsibility to make that determination, so anyone who is re-using code shown to them by this automated tool is doing it without having fulfilled their responsibility under the license. The fact that they don't know they are doing this, because the tool is not telling them, doesn't change that.
> People who publish MIT software know they're basically giving their code out with basically no strings attached.
No, they aren't. The license has terms. Using an automated tool that doesn't tell you when you are re-using existing licensed code, or whether your re-use is within the terms of the license, doesn't mean you can just ignore the license. It means you're re-using code without knowing whether or not you're violating a license.
In light of Google v. Oracle going as far as the Supreme Court I find your confidence in this quite astonishing.
I'm pretty sure every court will instead interpret the word "substantial" in the MIT license as referring to the concept of "substantial similarity", which must be demonstrated in any copyright infringement case - https://en.wikipedia.org/wiki/Substantial_similarity
I distribute software under the MIT. "Basically no strings" != "no strings". I expect attribution for any derived program which has substantial similarity to my software.
I regard the presence of the word 'substantial' to indicate that the license applies to even modified forms of the software. As that Wikipedia link points out:
> Under the doctrine of substantial similarity, a work can be found to infringe copyright even if the wording of text has been changed or visual or audible elements are altered