It's not clear whether by San Francisco this article is referring to Silicon Valley, but assuming that's the case - NYC has nowhere near the tech ecosystem that the Valley has in place. In the Valley you have the full gamut of software and hardware companies and everything in between.
In NYC, you have a mix of pure software startups that have had some success, combined with the typical industries which have deployed technology in a unique way (like Gilt Groupe - where, apparently, only 5% of the employees actually work in tech: http://gigaom.com/2011/11/22/gilt-groupe-ipo/ ), and the majority of software engineers in NYC still work for banks. It's going to take another decade to realize whether or not NYC has any real potential here.
That's only the case if you NYC intends to follow in Silicon Valley's exact footsteps. IMO, it would be stupid to.
As you say, NYC's tech ecosystem isn't as big. But its finance ecosystem is bigger. Also media, and fashion. I'm pretty confident that NYC can map out it's own path, playing to the city's strengths. I don't think it needs to have the same tech ecosystem that SV has.
