I seriously doubt if SF was ever leading in tech startups. I think you're confusing "digital media/entertainment" with "tech". SF is all about page ranks and eyeballs, just like TV channels are. Twitter is as much "tech" as Fox: each heavily depends on technology but hardly innovates/builds any.
I think Seattle, with their rich ecosystem of Microsoft-centric startups easily beats SV/SF as far as technology startups are concerned. Austin/Dallas duo is also tech-heavy, as well as Boston area.
Internet-media is only a niche and "technology" isn't just an alias to "web site", it actually has its own meaning.
I've lived and worked at startups in both places (Seattle, now SF), and the bay area is much more vibrant and active.
You're right that the bay area startups that you /hear/ about are largely media-oriented, but that's just confirmation bias. There are just tons of other startups and small companies that you don't hear about. In Seattle, people still look at you a little funny if you work at a startup (why wouldn't you just work at Microsoft or Amazon?)
I think Seattle, with their rich ecosystem of Microsoft-centric startups easily beats SV/SF as far as technology startups are concerned. Austin/Dallas duo is also tech-heavy, as well as Boston area.
Internet-media is only a niche and "technology" isn't just an alias to "web site", it actually has its own meaning.