Glad to see you posting here, Larken. :)
I posted a couple weeks ago about why I don't think we should honor the troops, and it really upset some people I know when I shared it on Facebook. The programming runs deep. Not sure what the answer is other than to keep broadcasting a counter message to hopefully reach some kind of balance point where rational thought can once again function. This is system 1/system 2 thinking stuff (have you read Thinking, Fast and Slow? I think you'd like it).
I would say that just because they didn't like hearing it does NOT mean you shouldn't have said it, nor does it mean it didn't make a difference. When they've heard the lie, day in and day out, for all of their lives, they will probably need to hear the truth a LOT before it starts to sink in.
Attacking someones world view is never an instantaneous "Oh, gee you are right". So yes sharing the idea may have set mental seeds that might take some time to sprout, but it could happen. That is what makes talking about these things never a waste of time.