As the purpose of Presidential pardons is to provide the opportunity to right significant miscarriages of justice in system that is almost impossible to get perfect, and that is the way they were typically used, it does not seem crazy that they exist.
What IS crazy is that they exist with very little consideration of a corrupt POTUS, judiciary, and/or congress. Seems the writings of the founders did worry about that significantly in later years, but evidently not in time to enshrine many guardrails in the US Constitution, not even a clear prohibition against self-pardon. Seems such a thing was considered so obviously wrong and corrupt that it didn't need to be mentioned. so here we are two and a half centuries later with people arguing that it should be possible.
I think that it does seem crazy that they exist. To give a single politician the power to simply override our justice system is dangerous and crazy. If that's really necessary in order to ovoid miscarriages of justice, then we need to fix the real problem, not introduce a new one.
Why is the pardon ability a problem? Because it's the judgement not just of one person, but of a person who is a political animal. There is no way that power will be used in a way that is impartial, and there is no single person who is so wise that they should be entrusted with such decisions. That it's a politician making the decisions all but guarantees that the decisions will be made out of political interest, not some interest in actual justice.
All the pardon power does is to increase the potential for corruption.
What IS crazy is that they exist with very little consideration of a corrupt POTUS, judiciary, and/or congress. Seems the writings of the founders did worry about that significantly in later years, but evidently not in time to enshrine many guardrails in the US Constitution, not even a clear prohibition against self-pardon. Seems such a thing was considered so obviously wrong and corrupt that it didn't need to be mentioned. so here we are two and a half centuries later with people arguing that it should be possible.