The problem is that unequally applies rules are often intermingled with biases. While a single instance of 'what about that other guy' isn't a worthwhile plea,

The problem is that unequally applies rules are often intermingled with biases. While a single instance of 'what about that other guy' isn't a worthwhile plea, if you can show a trend as to who gets pulled based on something other than speeding, you have a problem. In business, it is less of an issue because business doesn't need to be fair to the same standard of law. There are still certain laws and protect groups and such, but the bar is still much lower than in law. The complaint of unfairness can be valid, but also pointless.