MLK Jr did not like riots, and I can guarantee you that no one you're arguing with here does. Riots by their nature are destructive and unpleasant. That is the intention behind them, to force a demand that has been ignored through other more peaceful means. MLK Jr also became much more understanding of political violence in his later years as he became fed up with the lack of any meaningful progress with peaceful attempts at civil disobedience. Saying these things on the matter-
America would never have abolished slavery without the violence of the Civil War, and likewise the government would never have passed the Civil Rights Acts without rioting. It was not the peaceful protests that convinced people to do the right thing, it was threat of being harmed or killed. Keep in mind that during this era, MLK Jr was not viewed by most of white society as a peaceful man committed to non-violence. He was absolutely associated with the violent riots that occurred and viewed as the person who incited them.
This isn't true for most who promote those claims, take it from firsthand experience living in a family where about half of my mother's family (my grandmother's side) are extremely racist and full of literal KKK supporters and outright neo nazis. Holocaust denial is bullshit artistry by design. They don't genuinely believe it didn't happen. They know it did, and they know it killed millions. Saying it didn't gives them an opportunity to sell their idea that jews, socialists, unions, foreigners LGBTQ+ etc (all of the various groups who the nazis attempted to wipe out of existence) were never actually victims and that Hitler wasn't as bad as everyone says. And to dehumanize and spit on the people who died.
Behind closed doors within their close-knit family and friends (and I mean very close-knit as they have to trust you enough to let on what they really think), deniers admit they're aware it's a lie and not a genuine belief. An uncle of mine (my grandmother's brother) actually served in the US Army during WW2 and fought against the nazis. He hates German and Japanese people. Not because of the atrocities they committed, but because they were "dirty foreigners". In truth, he saw these atrocities and didn't deny they happened, but agreed with them. He just also happened to believe that the people committing them should also be gassed and burned alongside them due to their ethnicity. And he came home and instilled these beliefs in his children and grandchildren. They then instilled these same beliefs in their children, and so on. The uncle also taught his kids how to lie in order to better propagate their beliefs in society. They all know what they're saying is bullshit, but they laugh about it because it's just another way to dehumanize the people they hate and recruit others.