I think the advice is actually not bad, because the answer really is related to the kind of relationship you want to maintain and the kind of conversation you want to have in that moment. LW is talking about people that they have a distant relationship with, acquaintances and coworkers and the like, and I can see making the choice to say 'oh, how nice for you' to someone with whom you want to maintain a polite relationship with. If I told my coworker who was excited about her son's missionary trip that I thought missionary work is abhorrent and shouldn't be done in the modern world, I might end up getting hauled into HR.

In your situation, it's a little more complex. Do you know what Current Friend's politics are, or how much they value the valuable thing? I live in an generally very blue city in a county that's got some purple stripes, and I could very easily say to a friend "Yeah, I stopped talking to them when I found out they supported the insurrection," and know they would 100% understand my decision and would be just as horrified with me, and then we could decide together whether having the valuable thing was worth continuing to interact with this person and/or how much of a relationship accepting the thing would make me/us feel obliged to have.