Breaking into computer systems was already something that was happening then. Maybe they went a little overboard with the wording but it's not like Congress invented hacking.
Believe it or not but CFAA would likely have not come about if not for the classic film "WarGames" [1].
[1] https://books.google.com/books?id=7rBLCZuEOswC&pg=PA38&lpg=P...