[forgotpwd16]

This doesn't answer OP's question. OP asks why projects link to the page showing who starred them, not what some tool named stargazers does or/and what data can be gathered from people that starred a project.

edit: Thinking about it, probably does. Basically someone will check the stargazers page to find what people that have starred a particular project are up to or what else they may have found. This may seen as a waste of time on projects with numerous stars but becomes really useful in small niche projects with low number of stars.