The title of the post is "Want to Write a Compiler? Just Read These Two Papers." I upped the ante by proposing they just read one better paper.
I think if you had actually bothered to read the paper rather than make assumptions you would find the word "denotation" doesn't even appear in the paper.
I learned more about modern compilation by reading and implementing "From System F to Typed Assembly Language" than I did from the compilers course I took.