An Observation on Type Sizes

A short note to any book designers out there. The vast majority of commuters I observe reading Kindles have their on-screen type size set much, much larger than the default text setting. I think that this is an interesting observation, particularly given how people really avoid ever reading large-print books in public. (‘Oh, I don’t need to read a book with big type like that, my eyesight is just fine’.)
I do not know what percent of the publishing market is represented by large-print books, but it has got to be pretty niche. However, now that they have been empowered by the technology, people do tend to pump-up the type size to whatever setting they can read best at.
Perhaps we designers have been typesetting books in too small type sizes all along? A decision that up to now has always been constrained by the publishing economies of paper costs and the human ergonomics of carrying around larger books with massive page counts as much as it has by designer’s preferences for using small type sizes.
So perhaps the default type size for the next ebook you publish needs to be twice as large as what you have been using to date. Think about it.