Bad apples aren’t really a thing, bad leaders create cultures where bad behaviors are rewarded and encouraged instead of quashed while minor and prevented from growing out of control.
Nobody buys apples anymore. "A few bad apples spoils the bunch" is an aphorism based on the fact that ethylene gas increases the rate of fruit ripening and that rotten fruit gives off a lot of ethylene gas. Thus, if you have a spot of rot in your structure, your structure WILL be rotten if you don't tend to it. The aphorism dates back at least to mutherfucking Chaucer but, as with many of the malapropisms of this the darkest timeline, Patient Zero of this bullshit was Donald Rumsfeld who said Abu Graib was the work of "a few bad apples" which somehow means everyone else was entirely fucking fine. That Robert O'Brien applied Abu Graib logic to police violence says more than anything else; the solution then, as the solution now, is do exactly fuckall because it's not like it's your job on the line. The fact of the matter is, bad apples are a thing. NO leaders create cultures where bad behaviors are rewarded and encouraged because if you give out the same amount of praise and accolades to the violent, fun, lazy thing as the peaceful, lame, hard thing, violence will rule. The whole argument is now and has always been that the role of leadership is to get rid of the bad apples before they spoil the bunch.