the point is only to disable block damage. they can still hurt the player or knock the player in the Void but it would also prevent any further Griefing using them. because lets be honest.. you cant track who let the creeper explode...
~ @ToonMichaela
But additionally, having creepers unintentionally (not brought by other players) on the island risks them also blowing parts of it up (not due to other players), and this aspect I view as an inherent challenge in Skyblock.
As far as tracking, we may, or may not have a plugin, or other device, that may, or may not track what some, or all people do in some, or all servers in order to effectively handle issues such as this, or not such as this.