Likely because all of his supposed accusers have proven to be paid slanderers like you, or as often as not proved to be made up “sources” from media liars.
Having some experience with such weapons, I know that a modding an AR15 to full auto without breaking it is very difficult, yields a much higher fire rate than what we saw, and warps the barrel in about 10-15 seconds. An AK is much more likely, and WaPo is deliberatly ignoring the likelyhood that he bought a Soviet milspec one from the Mexican Cartels, who have millions of those.
Cue the libs slandering the man in 3, 2, 1… Oh wait they’re already spamming the hate.