Actually in matters of law (which this definitely is), "whataboutism" is just judicial or executive precedent.
This is like crying about whataboutism when a judge cites judicial precedent to justify a sentence. Good luck with that, it might work as a "nuh-uh" in online discussions but in real life, precedent does actually matter.
I understand what a precedent is in law and in life :) It seems like an illogical position to hold here.
Biden did bad pardons, now Trump has no other course (eg fix the system), but to do bad pardons as well? Except when Trump does it it is not bad because Biden did it first?