Jud Linville might not be the most popular person in Silicon Valley these days.

Last week Linville, chief executive of Citigroup’s credit card business, told Reuters that digital wallets hold little promise, something more than a few startups and tech companies are working on. “I’ve been around mobile for over a decade, with the notion that any day it’s going to dawn – just not this day or this year,” he said, despite the fact that Citi has a mobile wallet venture in the works with Google and MasterCard.

What’s going on here? What is Linville saying?

Linville, who joined Citi from American Express last September, shed some light on why he’s skeptical. Of mobile wallets, he said “this is a place where you’ve got to do a lot of little things and test your way into a whole bunch of different things. It is crazy to think that there’s going to be a one killer form factor. It’s still too early.”

I read Linville as hinting to the massive difficulty in getting to a point of interoperability. Other technologies have soared because they have either shown remarkable malleability, meaning that anyone can use and customize them, or because the service, in and of itself, is deeply valuable to users. Facebook is a good example of the first type of innovation. The Facebook model is one of indigenous flexibility. Google, on the other hand, is the quintessential service of deep value to users. The Google search engine is deeply valuable to users, but does not require others or additional software to make it so.

But neither dynamic is available to a digital wallet. In order for a digital wallet to work, it must offer both remarkable malleability and deep value to users, and for both those to be present, the digital wallet app will have to rely on several disparate parties. Just look at Citi’s partners in its mobile wallet venture. I can name five alternative teams of potential partners that would mirror the Citi/Google/MasterCard effort – and that’s just in the U.S.

Then consider what needs to take place in order for even a coordinated effort to get off the ground: “Test your way into a whole bunch of different things.” And Linville is probably underselling it somewhat. A bank like Citigroup does not just roll out products that “might” work. There are too many compliance and security risks for that.

The whole challenge of interoperability is so great, in my view, I am convinced that only the federal government can solve it. I know it seems distasteful to seek greater government involvement, but without a referee, there is the potential for payments bedlam to the detriment of every consumer in America. The average consumer will face foreign exchange costs from website to website and the potential for irretrievable funds locked into a random assortment of websites or payments vendors. That’s not to mention the susceptibility of fraud within such a freewheeling system. Only the government can fix this. Whether it will is another question, and one I fear the answer to which is “no.”