Social engineering is considered a form of hacking from what I remember of the CompTIA Sec+
People outside of tech have a wildly narrow definition of that word.
This book is not full of leet hacks, just quick and dirty tricks for sysadmins: Linux Server Hacks, Volume Two: Tips & Tools for Connecting, Monitoring, and Troubleshooting https://www.amazon.com/dp/0596100825/ref=cm_sw_r_cp_apa_48tNBbPJM2JVJ yet I am told all the time that "that's not hacking"