This is a little harsh and I doubt what the OP was saying. If someone interprets it like you suggested that is their problem. I don't see the implication that you NEED to live in SV to work in tech.
I don't think anyone claims that you can't find thriving tech communities outside of SV, but the reality that OP put forth is undeniably true. SV is where the most money is. SV is where most of the talent goes. SV churns out its own home grown talent through 2 of the best schools in the world. Did the automative industry all move to NY & Austin? No. They moved to SV (not exclusively, but I'm sure you've seen the map of automative companies moving in to SV).
Hollywood isn't the only place you can make movies and SV isn't the only place you can make software or start software based companies... but how are you going to deny that they are the most thriving communities in the world respectively?
