Last night, Uber CEO Dara Khosrowshahi gave some of his most expansive comments to date since taking the reins seven months ago concerning his vision for the company. Among them, he said he wanted Uber to expand its imprint on public transportation, which should raise some red flags for reasons I will soon outline.

Khosrowshahi said that Uber could eventually become a marketplace for other transportation providers, just like Amazon is a marketplace for third-party merchants today, and highlighted the variety of Uber’s existing businesses, which range from food delivery to trucking.

“I want to run the bus systems for a city,” Khosrowshahi said at an event sponsored by Goldman Sachs, according to the Financial Times. “I want you to be able to take an Uber and get into the subway… get out and have an Uber waiting for you.”

In some respects, this is old news. Uber has been tweaking its UberPool carpooling service over the last year to make it look more and more like a bus system — or at least a microtransit service. UberPool users in New York City can use pre-tax dollars normally reserved for transit trips to pay for rides. And UberHop, a service that debuted in Seattle a few years ago, was designed around fixed pickup and drop-off points, just like a bus.

In other cities, Uber receives government subsidies to supplement public transportation. In Summit, New Jersey, Uber gets money directly from the town to offer extremely cheap rides to commuters traveling to and from the local train station. Other towns, like Altamonte Springs, Florida, have gone a step further, totally replacing public transportation with subsidized Uber rides.