Tony Hoare / Historically Bad Ideas: "Null References: The Billion Dollar Mistake" (lambda-the-ultimate.org)

Once I read a book on compilers, can't recollect the name, that quoted Niklaus Wirth. Basically, he said that the hardest part in designing a language is to decide on what is to be left out. That idea and Hoare's reflection, seem to confirm the hypotheses that most woes in human endeavor seem to stem from gratuitous - often in hindsight, omission or commission to something.