I may be reading you wrong, you still sound upset here and I still don't understand why. (Unless my original guess was right: do you just mean that it's rude for better-off people to talk about their good fortune around others?) You've said, "blithely assume that there'll be money" (and earlier, "blatant displays of privileged ignorance"), but it's not clear why such negative language is warranted. If I expect to inherit some money when my parents die, I wouldn't call that a "blithe assumption": the odds are very good that it's true (and I know enough about their finances to have a basis for that belief).

I have no idea what the context of that original comment was, of course, so I can't really comment on how rude or out of place it would have seemed to me. The "spend/give money now to reduce later tax burden" idea is pretty much standard fare, in any case: it was certainly one of the first things discussed (and done) in my family when my grandparents approached the end of their lives. I'm very lucky to have grown up in a family that both had money to pass down and talked about how to preserve it for the next generation, and I think it's generally a good thing for anyone with a positive net worth to learn the basics (whether they plan to pass that money on to kids or cousins or charity or whatever else). So I'm a little uncomfortable with making the topic a complete taboo.

(Finally, I'm sorry to hear that you don't get along with that particular DaP/Mudd/CTY person. Assuming I'm not thinking of the wrong person, she's a good friend of mine.)