Yeah, but if you want privacy, it's a fine idea to prevent public networks and such from examining your traffic patterns. My personal main use case for a self-hosted VPN is for using public networks for private traffic, and I wouldn't suggest doing hardcore high volume piracy through such a thing.

The idea of using one for piracy is more focused on finding a VPS provider that can accept cryptocurrency and doesn't require your personal details.

Edit: whoops, realized I got the premises backwards in my earlier comment. Sorry about that.