I'm usually all with you on that complaint, but this case is different. They didn't promote Trump. They hosted a roundtable with him. Presumably, they would do the same with Biden were his campaign to request it.
Trump was trying to reach predominantly Democratic or non-voting black voters in Detroit by going to a predominantly black church, and he failed, pulling in a white crowd instead.
I agree they should be taxed. That being said, I don't know this man's goals, but inviting Trump to an open mic at a black church makes his son of a KKK member views just SO much more damaging. I really wish he got more offers like this.