Why do I need to sign up to something to use that software? It makes it seem like a scam. For example, look at this: https://www.zotero.org/ https://www.zotero.

Why do I need to sign up to something to use that software? It makes it seem like a scam. For example, look at this: https://www.zotero.org/ https://www.zotero.org/ There I just download it...