[svat]

In some ways, it's the opposite: Knuth is super practical and any theory is only in the service of whatever is actually relevant to writing better programs and getting answers. See e.g. this older comment of mine comparing CLRS and TAOCP: https://news.ycombinator.com/item?id=21924265 — where others may say O(lg n), Knuth will say that a trie search inspects an average of lg N + 1.33 bits for a successful search and lg N − 0.11 for an unsuccessful one.

But then again, as a result of all this work from him, pulling together and categorizing and cataloguing and analyzing all the disparate ad-hoc “tricks” that programmers had come up with, Knuth basically put (this area of) computer science on good foundations and made it a respectable academic discipline. So in that sense he successfully executed a Principia-like project.

To put it another way, the computer programming/algorithms world is generally divided into hackers who derive satisfaction from elegant ways of bending computers to their will, and theorists who are happy to talk asymptotics, treat their problems abstractly as a branch of mathematics, and often never write a single program. What sets Knuth apart is that he straddles both words: is firmly a hacker at heart, but is able to bring prodigious theoretical skill to bear on the area.