I think they mean more why it wasn't called something like "haveibeenowned.com" or "hacked.com". Not that they invented the term "pwned".
What does "pwned" mean? The word "pwned" has origins in video game culture and is a leetspeak derivation of the word "owned", due to the proximity of the "o" and "p" keys. It's typically used to imply that someone has been controlled or compromised, for example "I was pwned in the Adobe data breach". Read more about how "pwned" went from hacker slang to the internet's favourite taunt.