In general I'd agree that whataboutism is a logical fallacy, since it is basically a form of ad hominem, but it can also demonstrate that an attack itself is unjustified. For instance imagine if a farm was attacked for having laborers pick fruit for pennies per pound.

If one doesn't know much about the industry that would indeed sound potentially abusive - especially with sufficiently leading framing, yet it's also the global standard. That doesn't mean it's right, but it also means that allegations against one specific entity for such are, at the minimum, misleading.