A "siterip" for a service like K2S isn't about copying the website's HTML. It's about systematically downloading a specific user's entire collection of uploaded files. This is the primary use case for people seeking these tools.
Cyberlockers like Keep2Share maintain automated DMCA abuse reporting systems. Content creators and copyright enforcement agencies actively monitor indexing forums to submit takedown notices, which frequently results in links or entire uploader accounts being permanently deleted.