Why are Textbooks so Uninspiring?

I recently browsed through the 2010 edition of Halliday and Resnick Physics textbook. I used the 1965 edition, as a student. Besides the difference in price, and the pretty pictures, I do not see much there. On the other hand "The Feynman Lectures on Physics," written in 1961, still have that warmth of a work of love, intellectual love; Dick Feynman poured all his heart into that work. As you can see from his preface below, though, he was not satisfied.

In Mexico it doesn't really matter, the honchos that run the place as warlords, couldn't care less if Mexican students learn physics or not. A hero of mine Eng. Heberto Castillo, was almost killed because he wanted to change that situation, all he achieved, though, was a political party that is not what he wanted it to be.

The answer to the question posed in this note's title, in Mexico, is that people in power don't care. In the US, the situation is more nuanced, but at a gut feeling, I think that the reason Feynman's lectures were not promoted, and Halliday's book was, is greed, and money also.