I'd pin the turning point for dot-com culture at this year's Super Bowl. Though I can't claim to have seen the game myself, I understand it was peppered by a revolting string of dot-com ads--just like the ones all over our buses and subways and radio stations (even NPR!). That event marked the peak of dot-com chic. Essentially, dot-com turned mass market, and cheesy to boot.
What changed? For a long time, the Internet attracted the least risk averse. If you go with the Americana lore for a moment, the entrepreneurial character is supposed to be an attractive one. We certainly found that to be true in our recruiting here at TheStreet.com. Sure it was tough to find people back in '96. But the ones that did take the leap were creative, pioneering types, most of whom are still with us today. (Yes David, it could have been you, but you've done pretty well for yourself! As has Rob Walker [Slate's "Moneybox" columnist], who enjoyed a similar overture from me.)
In the last year or so, the nature of online recruiting has changed. Now people apply to dot-coms not because they're unafraid of the Net but because they're afraid of not being on the Net. Essentially, dot-coms have become the safe route. Safe is never stylish.
Your Columbia B School examples only send home the point. What was exciting (and exhausting) about the Internet four years ago (I think Slate launched around then, too) was building something new, brick by brick. These days, though, the Net is too often seen as the opposite--an easy path to $$$.
While the Net's in its tarnished period now, I think it will eventually cast off that stigma. Basically, the Web and e-mail are becoming so integrated into "actual" culture that "virtual" won't be a separate label for much longer. Every "real" company will have a Web arm, every Web company some real-world "brand extension."
Who knows, maybe soon enough the Net will become so unremarkable that we'll be spared magazine essays from the chattering classes every time they have their first shopping experience online. Wishful thinking?