Are you arguing that the Eternal September effect doesn't exist? Because having been seen the effect first hand in no less than a dozen different online communities over the years, I can confidently say that it very much does exist.
But this is in regards to specific sites and communities; "The Net" has long since become too large to be considered a single community.
Yeah, my experiences on the late-90s, early-2000s internet don't support the idea that some level of technical aptitude correlates to a desire to share anything other than drivel.
Timecube, dancing babies, blink/marquee tags, MIDI music backgrounds on yet another "hey look at these pictures of the new muffler I put on my car!" site... ah, the good ol' days.
I honestly haven't noticed any increase in drivel, as a proportion of overall content, on the web now compared to when I first got on in 1998.
And before that, there were many fountains of ignorance to be found on Usenet (alt.* :), Archie, Gopher...
It was in general a smaller community, and that kept the amount of drivel small, too. But it wasn't all as rosy as you seem to remember.