What does the cryptic crossword clue "Not just amusement parks have ditched their extreme characters (6)" mean?

The definition is "Not just". The wordplay uses a deletion. UNFAIR (deletion) + (deletion) = UNFAIR; definition: "Not just" The answer is UNFAIR.

Not just amusement parks have ditched their extreme characters (6)

Times Cryptic #28603 | 10 Across | 2023-05-15 flower