This ultimately results in less feeder traffic for the subway, higher subsidy requirements and is overall a bad thing for the system.
Über's valuation is all about the market clout they are building. The fantasies of robot cabs are just a veneer.
"The theory of disruptive innovation was invented by Clayton Christensen, of Harvard Business School, in his book “The Innovator’s Dilemma”. Mr Christensen used the term to describe innovations that create new markets by discovering new categories of customers. They do this partly by harnessing new technologies but also by developing new business models and exploiting old technologies in new ways. He contrasted disruptive innovation with sustaining innovation, which simply improves existing products. Personal computers, for example, were disruptive innovations because they created a new mass market for computers; previously, expensive mainframe computers had been sold only to big companies and research universities."
[0] - https://www.crunchbase.com/organization/uber/funding-rounds [1] - http://money.cnn.com/2012/05/31/news/economy/nyc-subway-cons...
I'd arguing that Uber has the potential to pose a disruptive threat to taxis, not subways. And to lots of transportation systems in plenty of other cities around the world.