Hans,

 > Meta reasoning from the impression of TeX I get, developed as a series
 > smart, but quick features lacking true generality and depth, I surmise that

that's a bold statement from you, given that TeX though being more than 20
years old has still to find a opponent program that can produce even equal
quality in its domain.

you might argue that Don as a language designer isn't really strong but that is
only a part of the story (though with most of your comments my feeling is that
you think it is all that is about anything)

 > any attempt in developing a TeX successor by enhancing it will fail.

possibly but not for the reasons you claim

frank