I don't often reply on Hacker News, but when I do, I post it here too because I wrote much wordses.
Excellent article, and I feel it applies to me. maqr's comment about this being dangerously close to social engineering rings very true, although I doubt that it's intentional/by choice. Personally I've never had a lot of natural conversational skills, so I find myself falling back to old tricks that work at times when I'm not confident, and sometimes they happen to be tricks that relate to social engineering. I'd like to think that this doesn't make my interactions less genuine. Finding a polite way to proceed through the conversation has not been a problem for me since I learned this.
Lately, rather than moving towards politeness, I'm trying to move away from it. The examples of always replying positively to people, never steering towards or even approach hostility is a very, very tiring path to walk. In my experience, it does pay off on the whole, but I've spent a lot of time talking to people that were just never 'interesting' or 'rewarding' to be with, simply because it always seems easier to please than to confront.
These days I'm trying to move towards blunt honesty with people as soon as I can (after an initial period of polite conversation to gauge if they'd be comfortable with it). So far, I think the people I know appreciate me more for it, and the people who wouldn't appreciate me for it are not in my life.
Or perhaps it just feels good to try something different.