There's no theory of competition that expects incumbents to allow their own infrastructure to be used against them.

But you're right, if the article is correct, we should expect Uber and Lyft to fight tooth and nail to provide the better product for consumers, which is the beauty of competition. They do all the work and take all the risk, we get almost all the benefit. Both companies seem uniquely placed to have exactly zero chance of capturing regulatory favours.

It's not necessarily a competition thing though, is it. Intermediaries sit on top of them, rather than competing. And they rise in many industries because they can provide value that suppliers can't. In the travel industry, consumers want (for example) the cheapest rates on elements of holidays, hotels etc. So price comparison sites happened. Suppliers can't do anything about this in terms of competition, because the intermediary has a value proposition that the suppliers can't offer which the market wants, and the suppliers want the sales anyway.

With ride sharing, consumers presumably want the cheapest, quickest, cleanest fleet. I doubt fist-bumps really factor in to the experience. Suppliers can improve their fleet, improve their drivers and so on, using their own perspective as a guide. Aggregators can offer the cheapest, quickest, cleanest fleets to the market without having the limited perspective. They get a better view of the market through this too, potentially adding value to the whole supply chain.

Incumbents don't have to allow their own infrastructure to be "used against them", but they will, because this is what the market wants.