Is it just that I'm a fan, having read [1] as a science student? I don't think so, because when I recommend that essay to a student who is frustrated with msword, I almost always get a report about how intriguing it is.
Beyond the material, I think a big factor is that it's simply intriguing to hear what a clear thinker spends time thinking about.
1. Knuth, Donald E. “Mathematical Typography.” Bull. Amer. Math. Soc. (N.S.) 1, no. 2 (March 1979): 337–72 https://projecteuclid.org:443/euclid.bams/1183544082