2/3 to 3/4 of the Western world disagrees with you. Every poll ever done in the West in the last 30 years has confirmed this fact. The House Select Committee on Assassinations, which did a far more thorough investigation than the Warren Commission's sham, also disagreed with you.
Indeed, we now know that three members of the Warren Commission itself did not believe the lone-gunman-no-conspiracy scenario. We also know that Robert F. Kennedy and Jackie Kennedy strongly believed that JFK was killed by a conspiracy, even though they publicly endorsed the Warren Report.
Now, getting back to the subject of this thread, i.e., the military commission's guilty verdicts against the accused Lincoln assassination conspirators, there is wide agreement among historians that the commission was a kangaroo court that relied heavily on bogus evidence and coerced testimony. There is especially wide agreement that the commission's case against Mary Surratt was not only fraudulent but vicious and malicious.
Thomas Bogar's 2013 book Backstage at the Lincoln Assassination: The Untold Story of the Actors and Stagehands at Ford's Theatre broke new ground in the case, exposed considerable fraud in the military commission, and received effusive praise from such Booth scholars as Terry Alford, Michael Kauffman, and Daniel Stashower.
Robert Redford's 2010 movie The Conspirator, although it got some details wrong, did a good job of presenting some of the holes in the case against Mary Surratt and especially in exposing the kangaroo-court nature of the military commission.