> What you are advocating for it a system where professors can do anything they want and them simply blackball the student who makes a legitimate complaint and have all their professor friends do the same.
No.
I hear that you had bad experiences. That said, the right to challenge one's accuser dates back hundreds of years. It has survived as a foundational principle across millions of legal cases across all domains and including astronomical numbers of cases in which parties on either sides of the arguments have faced as much or more collusion risk than is claimed here. Anyone who thinks they can just type a few words into an internet comment thread and construct a legal system that better handles all the subtleties and realities of actual proceedings than we have in our court system today is either mistaken or the greatest legal mind in millennia.
The problem is not that we need you to try to invent a better system than the US legal system. The problem instead is we need to stop allowing bogus pretend legal systems that administrators at universities and similar institutions have tried to put in place using similarly naive legal theories. Those administrators suffer from the same hubris as anyone who thinks they can just sit down and write up how to do a functioning legal system in a paragraph or two. Each such system is deeply flawed in a different way, but all are deeply flawed. Real world accusations are always hard and messy, regardless of the domain, and coming to the correct resolution is never as easy as a one sentence "correction" to hundreds of years of jurisprudence would like to imply.
The "legal" systems constructed by these administrators are indeed deeply flawed, but arguing against core legal principals that have formed the foundations of legal theory for hundreds of years is not likely to be the path to improvement (and if it were to be, one is probably better off taking that once in a millenium legal insight in other directions of far greater impact to the world than complaining about a particular university's poorly conceived dispute structure).