Until you can prove to me that all courts, judges, attorneys, and juries are above reproach and no innocent people are imprisoned there absolutely should be a method for someone to pardon. Sometimes a pardon will be issued for people you disagree with, but that’s part of it. Just like somebody will say something that pisses you off, but that’s the cost of free speech
A single person should never have the sole power to undo an unlimited number of lawful convictions. It seems like a power designed for corruption.