Note they totally about it being a thing that happens partly because devs are volunteers. There are things that are more important than they are interesting.
This is not a "how devs should behave" paper, it's an economics paper.
Underproduction is a meaningful term in economics, where it refers to the way collective action problems cause a gap between a socially-desirable outcome and the actual outcome.
However, from skimming the paper, this does not seem to be the direct source of the term. The authors appear to adopt it from Gorbatai[0], who is apparently using the economic term without defining it or referring to literature about underproduction generally. That means the authors of this paper may be unaware of the depth of economic literature in this field.
[0] https://opensym.org/ws2011/_media/proceedings%253Ap205-gorba...
Sorry if this comes across as defensive -- I know the authors, so am very certain that they are aware of the rich literature on collective action problems and public goods.
It's the latter which have been the most important developments in the past 70 or 80 years (starting with, say, Coase), because they so radically modify and constrain the applicability of pure theories of supply and demand. "Underproduction" belongs to these later developments.
If I am making something for free, or for minimum amount of money, or based on unstable funding - then I am doing because I want to do it, and because I produce something that I like or want to exist.
Obviously, I am not going to code features useful for oversized corporation that are neither useful nor interesting for me. If they want this features - they will need to hire people, and it is not my problem.