Hmm. I am not sure this is about stupid. I don't think the web is dumber than Usenet. It just requires a lot less work to find something interesting. On the web you find organized sites that know their topic pretty well and have pre-filtered posts (like Slashdot). You get more bang for your buck, as it will. That's not stupid; it's smart--it's economics.
Usenet is less fragemented, which is an advantage. It's a nexus for discussion of all sorts. You can wander from one genre to the next easily. If conversation was all people wanted--if their primary reason for logging on was to find random users and chat--Usenet would probably be more popular than it is.
I've no doubt that configuration entered into it, but Usenet could have tried to reach its tendrils into the web, to become a more integral part of it. I can't even begin to figure out how that would work, but if Usenet was the primary commenting engine behind web sites, maybe you could navigate to the rest of Usenet from there. I mean, you and I are already in a conversational mood. At this point we're probably both in a space where we would enjoy Usenet for a while.