Because given the opportunity a certain percentage of the population will commit lawless acts. We saw this all last year. Suddenly when it's 400 Trump supporters it's an insurrection. When it was thosands of BLM, it was peaceful protests.
Only 7% of those who caused trouble of the hundreds of thousands of people who were marching for civil rights. That means 93% protested peacefully. And as reports came out over time there were many cases of white supremacists who created and participated in riots and violence.
I notice you conservative won't mention that 93% protested and marched peacefully, and that's because you don't want black and white people marching for civil rights are decent people people.
Contrast that to all the people at the Jan 6 event who believed disinformation, mostly from trump, that there was election fraud and there had to be a protest against our election. Who among those people were decent and sane? That a large percentage, over 600 now identified and charges filed, broke into the Capitol seems smaller in proportion to the civil rights marches, well good. It's good that more citizens marched for civil rights than held a riot and attacked the USA.
Which side do you want to be on? Civil rights, or anti-democracy?