Dijkstra was wrong about ALGOL 68. ALGOL 68 was much better than the ALGOL W proposed by Wirth, or than its successor, Pascal, or than any of the languages designed later by Wirth.

Moreover, even the report about ALGOL 68 was not bad as a tool for a compiler designer who must search through it which is the correct syntax for various language features. The ALGOL 68 report even contained some subtle humor.

However where ALGOL 68 was a complete failure was that Van Wijngaarden and his collaborators did not publish any other document about ALGOL 68, except the Report.

The Report was completely unsuitable as the first document used by someone who wanted to know what ALGOL 68 is and what it does.

The only way in which ALGOL 68 could have succeeded as a language would have been if Van Wijngaarden would have published at least 3 documents to be read before reading the Report: a tutorial presenting programming examples of using ALGOL 68, a rationale for the design choices of the language (like the designers of the Ada language have published at its introduction) and a document explaining how the Report with the formal specification of the language has to be read.

Without these preliminary documents, the Report about ALGOL 68 looked too alien and it required too much effort to reverse engineer how it is supposed to be understood that even people with the experience of Dijkstra did not bother to make the effort to understand it, so they never knew whether there actually is something valuable in the report or not.

Many years ago, when I have seen for the first time the ALGOL 68 Report, my first thought was also that this must be some kind of useless garbage, and I did not read it. Only years later I tried again and that time I read most of it, so I could see that actually many important programming language features were described there for the first time, and some of them were actually better in ALGOL 68 than in later languages.

I really cannot understand what was in the mind of Van Wijngaarden, how could he believe that publishing this report alone, without accompanying it with a set of explanatory documents, would be enough for other people to learn what ALGOL 68 is. His reputation has certainly suffered after the publication of this report, so whichever was his reason to not write and publish more at that time, it was a wrong decision for his career.