I'd say having Google in NYC is probably a negative for startups. Most of the good talent gets soaked up by the big G,

And your 7 minutes to work as an engineer, is actually a bad thing for startups. If a programmer lives in Manhattan(sub ~50s st), then he is paying ~$3000/mo for an apartment. If you are stuck with a $3K fixed cost every month, it's hard to quit a job to go do your own thing. Granted, you can always get a cheaper place, but most programmers with 2-3+ years experience seem to be making ~$100K+ in NYC, so they tend to justify spending a bit more to be closer to work