If the buyer cannot estimate the quality of the product before buying, the sellers will reduce quality or be forced to by competition. Buyers lose trust and the market can collapse.
The reason why people don't pay for online stuff is mostly because we're used to get free stuff online + the fact that online payment remains cumbersome (even moreso since the businesses have all incentives to pish you to a regular payment model instead of a one-shot one). It has nothing to do with information asymmetry.
And that a paper that reads like a parables like this was deemed Nobel-prize worthy tells us more about economics as an academic field than about the paper itself.