Equivalent arguments exist for Ruby. Ruby isn’t bad because someone wrote a DSL that should’ve been a method and maybe a hash.
I actually had heard of at least KRC and Miranda even before the first time I've read the paper, but even if I hadn't I would immediately be able to think of several languages with some or all of the additional features over the Lisps he was comparing them to for which he describes them as superior to Lisp for the purpose, including some modern Lisp derivatives.
Pattern matching, mathematical notation, and static typing with use defined types are all features that have become more, not less, common in languages since the paper was written.
I happen to own a copy of HTDP which I bought for the course. It's a suggested textbook but not required at all. I haven't had time to go through it though.
When you actually start using these languages, you find yourself tempted to leverage this property and try writing lots of macros. But then you go back to the community and everyone tells you "the first rule of macros is you don't write macros." It turns out that if you use macros all over the place then your code becomes impenetrable. The problem is that macros allow you to circumvent the expected order of evaluation and produce your own novel syntactic structures. This puts lie to the old claim "Lisp has no syntax." In reality, Lisp has tons of syntax, it's just informal and buried within the definitions of macros.
It parallels the problem put forth in Jo Freeman's famous piece, "The Tyranny of Structurelessness" [1]. Any group that purports to adopt a structureless organization ends up having a hidden, informal structure. This is the way of Lisps as well.
[1] https://www.jofreeman.com/joreen/tyranny.htm