«Couch arguments» involve scorn, dirty looks, and nervous laughter, with
a generous side order of judgmental proselytizing.
For instance, if one platform charges a high fee to one
side of the market in
order to subsidize another
side of the market (say, by offering
generous rewards), this creates an opportunity for a savvy competitor to undermine that balancing by charging the first
side of the market a lower fee, thus attracting consumers from its competitor and, perhaps, making its pricing strategy unprofitable.