As an extreme example, consider murder. Obviously it should be illegal, but if it's legal for one group and not for another, the group for which it's illegal will probably be wiped out, having lost the ability to avenge deaths in the group.
It's much more important that laws are applied impartially and equally than that they are even a tiny bit reasonable.
Laws and their enforcement are a clusterfuck. To achieve greater justice we should strive towards better judgements overall.
God, stop with the group on group bs please and engage with things the way they're written without injecting the entirety of your cynical worldview layered on top.
Furthermore, group affiliation based differences in judicial decisions are very common, both when it comes to ethnic origin, wealth and profession.
In this case group affiliation is also directly relevant: individuals who have infringed copyright are typically not treated in the way that these firms that have infringed copyright are. The group affiliation in question is thus 'are you an employer/wealth person owning part of a large firm' vs 'a normal, non-employer/non-wealthy person'.
If there are precedents with a certain application, then they must continue or be overturned generally.
Correct but uneven application of a law is more dangerous than incorrect but even application.