i think the main argument for leaving it default is [1] for any additional/new sysadmin that has to touch the system. but imo this goes both ways; i'd rather not have my house key hidden under my doormat, where every burglar can check for it in a few seconds. if i taped the key to a random tree branch (even in plain sight), it would be a much safer bet.
[1] https://en.wikipedia.org/wiki/Principle_of_least_astonishmen...