I *get* the distrust and even scorn that a lot of people have toward the entire concepts of "procedure" and "due process (for the political enemies of human decency)", but:
The main problem is that the substantive and procedural rules that exist today are unfair, and *they can be changed*.
The injustice inherent to our capitalist society affects both "the law" (colloquially) and procedure — for example: on the substantive side, the fact that businesses and governments are not at all liable for social murder; on the procedure side, that wealthy litigants in civil proceedings can out-spend less wealthy litigants and win not based on the merits of the actual cases, but just bankrupting their opponent. (Among many more examples for each.)