How I see it, it's like tipping your hat off to a TV series like the Cosby Show or A Different World due to its positive representation, but at the same time acknowledging that Bill Cosby is a rapist.
Everybody has skeletons. The only difference is that when you're famous those skeletons become public. You can acknowledge someone for making great contributions or advancing the culture while holding them accountable for their horrific and poor actions.
If people want to cancel Kwanzaa because of Karenga, that's their choice. People are free to do that, but if they're going to call out others for doing so, then I have to address the hypocrisy. Why do we vote in elections? Why did so many black people shout hip hip hooray when Joe Biden won? Is he going to save black people and other marginalized communities? Is he going to end imperialism abroad? OR did he just beat the guy whose problems are painfully obvious? Even at the state and local level how many US politicians have a squeaky clean record for not screwing people over? To stay closer to the topic...why do we celebrate any American holiday? They were either started by problematic people or the modern commercialized versions exploit workers and nudge the public to participate in consumerism.