Loads of Reddit/HN posts are adverts. We all click on adverts all the time, all over the internet. We just don't necessarily realize they're adverts.
Yes, shock horror, adblock only blocks the most obvious advertising.
You're just using different semantics for "advertisement." When people talk about advertising they mean something more direct; where an advertiser pays a content-provider to insert arbitrary content. In terms of a user experience, that kind of advertising is more adverse than what you're talking about. The point isn't "shock horror I might get tricked into visiting some site where someone is sellign something", the point is that advertising is distracting, disruptive and negatively impacts the value of the core product.
Dozens of blogs exist primarily for marketing reasons, to get linked from reddit and hacker news and such. That doesn't make them "advertising" in the same sense that a picture of a hot teenage girl hawking a dating site in the corner of my facebook profile is "advertising."
- Video/audio advertisements that start playing by themselves = I'll probably add you to my mental black list of people and companies I don't want to do business with (yes, I have one, 'voting by my dollars'. Actually, Groupon is on it, mostly because of annoying ads that were just everywhere I looked.).
- Pop-ups and anything that touches the area with content (all those floating or expanding windows), distracting me in an offensive way = I'll most likely remember you as a company not to do business with you as well. Also, I'll start hating the website soon for allowing this type of advertisements.
- Simple banners and ads of products that in my belief actually introduce some value - like development tools - I don't really mind them; I might click on then to see what's about with this new product, out of pure curiosity.
- AdWords - I don't mind them, they're not intrusive. I might even consider clicking at them if they happen to show something interesting.
Also, I can't even express how annoyed I am about the new batch of YouTube adverts - the ones that play before the movie I requested, often stealing half a minute of my time and making me lose interest in the video itself.
So yes, AdBlock is fine. It blocks most of the crap.