To be clear first: The parent is being a little unreasonable.

However.

There's no need to resort to insults, nor to use a single person as an example, which doesn't make sense, regardless of whether it's their "only hobby".

Average novel reading speed is an impossible metric. E.g. WPM measurements are irrelevant to long-form reading, are irrelevant to literary reading, and don't account for processing, tangential thought, or re-reading, which are of course highly variable. And "reading time" (the subset of free time conducive to literary reading) is also basically impossible to quantify broadly. It's also difficult to categorize people by how much they are trying to read. Some people are only a little interested, some not at all. Further, this is one of those fields where the super-humans aren't actually that rare, so you get a situation where the average person reads 8 books per year despite half of all people reading half a book per year (made up numbers).

Point of all that being, "novels a year" is one of the most culturally acceptable brags, because there is no "expected" value for people broadly. It's a hidden value, so we can say things like "yeah, I read 12 books a year, not a lot I know", and people generally won't roll their eyes at risk of appearing stupid.

Look at how many people on otherwise-rational HN are saying "I used to read 30 novels a year," "I used to read a novel a week," as if that means it must be easy to accomplish in Western work and life culture. We're drunk on the ease of implicitly painting people who can't read as much as us as simply dumb modern westerners.

I think it's an easy thing to do, and we shouldn't. It's not classy.