One was for equal rights and the other was to overthrow the federal government. A lot of the perceived leniency for the protesters was due to the brutal arrests and a lack of Miranda rights. Don’t forget that they shot at the protesters and not the insurrectionists. The sentences were not out of the kindness of the judges hearts, it was due to the unlawful arrests.

Federal property was also involved in the insurrection so I don’t really follow your argument.