TeX is optimized for the quality of typesetting. This is not very important for us.
HTML is all about creating links. This is exactly what we need. After all, scientific publishing is for linking ideas.
TeX+PDF has a serious disadvantage: the document gets split, in an arbitrary way, into pages of fixed size. This is just harmful.
TeX does not have a convincing support for internationalization; in its basic form, it is essentially English only. Exist various extensions allowing to overcome this, but they are confusing and unstable
Practically, TeX is very hard to learn, and hard to use properly. With the right markup tools (perhaps this project?) HTML should be easier.
Learning Lisp/Scheme/Racket is a rewarding intellectual experience.