[kej]

Scammers don't need this to copy an existing website, and I could see plenty of legitimate uses. Maybe you're redoing the website but want to keep the previous site around somewhere, or you want an easy way to archive a site for future reference. Maybe you're tired of paying for some hosted CMS but you want to keep the content.

[meiraleal]

All the scenarios you described can be achieved by having access to the source code, assuming you own it.

[kej]

Lots of things are possible with access to source code that are still easier when someone writes a tool for that scenario.

[meiraleal]

Crawling a build you already have isn't one of them

[p4bl0]

The website in question may be a dynamic website (e.g., WordPress, MediaWiki, or whatever other CMS or custom web app) and you either want a snapshot of it for backup, or you run it locally and want un static copy to host it elsewhere that only support static files.