A lot of people wrote a lot of programs that were a lot simpler and more compact because they were able to assume that, for instance, one byte was one character. Back in the 70s it made little sense to waste precious time and space in processing text to take into account issues that would become critical decades later.
Furthermore you're acting as if i18n issues are something that are easily dealt with if you've chose to deal with them. This seems to me to be absurdly wrong.
Getting i18n right takes a lot of knowledge, and speaking to a random competent typographer wouldn't magically solve the problem. Oh, it might solve your problem, sorta. You could just add some extra characters for some European languages. But you quickly get to too many characters for one byte, and don't handle people who use different alphabets. You've also made life harder for whoever wanted to solve the problem for real later. (Something like UTF-8 would have been impossible.) You could take a few to use for combining characters (letting people say something like `e and have it be one character), but you'd probably miss the issue of multiple combining characters. You could try to create an extensible system, and invariably you'd overdesign.
In fact this is an example where I'd accuse Todd of setting impossible standards for others. Suppose that they did try to solve i18n back in the 70's. Inevitably it would have caused computers to waste memory and run more slowly, and the design would have sucked (without experience trying to solve the problem, you're unlikely to come up with the right abstraction). The alternative is to try to solve the problem incrementally - solve the problem that you have now, now, in a way that can be extended later when you have a better idea how to do it. Normally Todd would be all over that approach, but not in this case. Because many different people tried to improve the system independently, each of them solved their own problem, and their solutions conflict.
So if they overabstracted then he'd blast them for overabstracting and coming up with a bad solution, while what they did gets them accused of being xenophobic and causing a long-term mess. Neither way could they win.
If you think that my summary is wrong, tell me what you think should have been done, within the needs and limitations of 70's technology, to solve i18n. Or did you only care about them finding a practical solution to your problems, leaving other people in the cold? (In which case you're no better than they were...)