First off people cannot (or at least should not under T&C of the this site) share the zip file.
Second (and I stand to be corrected by MOD ) the reason the comments cannot remain somewhere is that all files and related content (e.g. feedback or comments) belong to the author not TF, and if as it possible (and do not want to start speculating here) there is a legal reason behind a file’s removal then leaving the comments available would only potentially fuel any issue relating to it.
Hope this helps
You got it
I don’t know the legal reasons the author talked about, nor do I need too. If the author wants to remove the file, then he is completely within his rights to do so. And no, you cannot share the zip file among multiple users.