I think that's the wrong conclusion to draw.
Advertising on web sites works very, very well and thousands of companies depend on it on a daily basis.
What doesn't work so well is advertising on a web site that's just an online version of a magazine. The problem has a lot more to do with the magazine part than the web site aspect.
I've been reading DrDobbs for a couple of decades and I'm a fan, but the simple truth is that it's become less relevant these past years. First switching to a download only model and then progressively nagging me pretty aggressively to download my own issue (which I stopped doing because the summaries I saw in the email were of little interest to me).
Andrew, reading your editorials has always been a pleasure and you should be proud of what you accomplished.