The article actually focuses primarily on pre-revenue and/or pre-profitability consumer-oriented startups. While these companies do make a fair share of headlines and noise in both the tech and the mainstream media, I would hardly say that it makes up a large percentage of the *actual* jobs and capitalization of either the tech sector as a whole, or even the tech sector in silicon valley.
While the author does make some good points with regards to over-valuation of these companies (and some of the crazy things that some companies may be doing to attract top-level talent), his comparisons to the late-90s dotcom bubble is weak at best. (I know from personal experience, as I entered into the workforce during the boom and got to experience first hand the woes of the bust).
The original dotcom bust had such an impact on the overall economy because a majority of the investment and valuation was on these non-profitability consumer-oriented businesses (pets.com, etoys, govworks, etc.). The current tech sector economy is *significantly* more diverse, with strong B2B startups, hardware and consumer electronics, platforms and services, etc.
However, note that the focus of the article is *only* on consumer-oriented startups. His graph on Andreessen Horowitz (ironically, founded by former Netscape founder Marc Andreessen, who was one of the poster boys of the first docom bust) I think nails is perfectly: "Andreessen Horowitz
So in the article itself, the author specifies that there is still a very strong market for B2B companies. Who are these companies? Most of us probably have never heard of them, and likely never will. Because most of them are boring, unsexy companies that help provide business improvement, revenue generation and/or process efficiency in industries that will never make it on to VentureBeat or Tech Crunch. However, they are also boring, unsexy companies that add *actual* value to businesses, which in turn provides revenue and profitability to the company, which I would argue is a significantly stronger driver to the tech economy than the B2C startups.
To say "tech sector" and "silicon valley" and to only attribute it to the flashier B2C, consumer-oriented startups is simply perpetuating the disservice that the tech media gives to the women and men who are and will continue to be the true drivers of this economy.