For prospective multicultural employees, suppliers, investors, and business partners, the current universe of Silicon Valley keiretsus represents a substantial barrier to entry and, largely, explains the severe paucity of diverse employees, suppliers, partners and investors in Silicon Valley companies.
We have a thriving tech community, but also a wealth of other industries in New York. Great products and innovations get built when there's a high-bandwidth link between the builders and the customers of those products, and so NYC is the right place to be if you want to disrupt one of the few trillion dollars of industries headquartered here.
The biggest difference a place like HBO and a broadcast network (ABC, CBS, NBC, FOX) is that HBO is a pay service and the networks are ad-driven. The networks have sponsors they have to keep happy. They need eyeballs to charge the rates they charge. They need to make sure they don't offend anyone. They have to make sure that people aren't using competing products on their shows.