[skissane]

So, if you include N different MIT-licensed libraries in your app, you have to remember to ship N different third party copyright licenses in your binary (or documentation shipping with the binary). And you need to keep an eye out if they change – if you add or remove a third party library, or if a third party library adds the name of a new contributor to its copyright notice in a newer version.

It gets even worse when you consider that there are MIT-like licenses, which can have fundamentally the same terms as MIT, but with slightly different wording. Then you can have to ship multiple variant license texts too.

Public domain (and public domain-equivalent licenses) you don't have to worry about this, because there is no requirement to include copyright notices or copy of license text.

I'm not saying you shouldn't credit people whose contributions you use, but you can make that a non-legal expectation of courtesy rather than a make-work legal requirement.