If you're a small company (like a 2 or 3 person startup, ie. the HN crowd), then you are the face of the company doing the tweeting/blogging/whatever. Sure, don't fool yourself that your couple hundred followers really care all that much, but it's cheap and easy marketing, and sometimes you get a bite.
I may be wrong, but this seems like just a rage dump.
I don't work for a large corporation so I can't say how they treat this stuff, but the way we're approaching this is "starting conversations."
In addition, if you don't have any presense, how will you be found? If we stop posting blogs, making websites, using twitter and all the other tools we have to get our message out (and linked to) how would the author want us to be found? We could go back to the old days of directly calling prospects who weren't even looking for us. I just love getting unexpected phone calls from salesmen myself.
I understand that you (part of a small company, I presume) have a need to be found, but the author is in fact right when he says that blogging and tweeting by companies is really just advertising, nothing more and nothing less. Most people do not "start conversations" with companies, they start conversations with other people.
What company blogs and tweets and Facebook fan pages are, of course, good for, is providing an avenue for companies to push their marketing onto consumers that care so much about the product they've actually subscribed to the blog, twitter account and Facebook page without bothering anyone else. In that sense they're a huge improvement over traditional advertising. That does not mean, however, that they're not still just that: advertising.
If you're a small company (like a 2 or 3 person startup, ie. the HN crowd), then you are the face of the company doing the tweeting/blogging/whatever. Sure, don't fool yourself that your couple hundred followers really care all that much, but it's cheap and easy marketing, and sometimes you get a bite.