Why do debuggers need an admin password? Why does running LLDB or instruments require elevated privilages?
Scanning protected memory is something only something authorized (in this case authenticated) sudoers are able to do.

Not requiring this would be a huge security risk and is part of the reason Windows from the 90's and early 00's was at higher risk of virus infection.  An application could easily dip into the memory partition of another application, viewing or modifying its contents or inserting arbitrary executable code.