If you look at the repo, the very first line in the readme links to an issue that briefly explains why you should care.
Unmaintained software comes in two categories:
The software is done. It does exactly what it was meant to do and it was written in a language and in such a way as to be pretty future proof. Examples are some basic code libraries or command line utilities.
The software had to be updated all the time to keep up with changing environments and security problems, so the dev got sick of it and dropped it. Or a better solution came along so the developer felt free to finally drop the burden.
Nativefier falls in the second category and the second clause. Don’t use it.