I can understand why the author is angry at TeX, but I think it's mainly a misunderstanding. TeX is very low-level, it was designed that way and never pretended to be anything else. That's why people created macros around it, and LaTeX is the most successful of them.

I happen to have worked on many document generation systems in my career, I have written systems targetting odt, docx, postscript, and pdf, either from scratch (for odt and docx) or xsl/fo (ps), docbook (pdf) or TeX/LaTeX (pdf).

The most satisfying, easy-to-build, but not the easiest-to-understand, the one that gave the best result in terms of time-to-develop/quality/satisfaction was TeX/LaTeX. So sure, the math can suck in TeX, maybe, I don't know (didn't feel that way at uni when I was using it for that), but as a typesettings low-level language to target, it does a very good job.

Also I fail to see how TeX is an issue, or even how it prevents competition to happen, when all it takes is writing a better front-end language for it.