“hated.” This is one of the places where “hate” refers to something that a person did not choose, and thus did not support and pay attention to, but instead chose something else. One of the standard Semitic definitions of “hate” was “to “ignore, neglect, love less” or “not choose someone or something,” instead choosing someone or something else.
The immediate and remoter contexts of this verse lead us to believe that “not choose, ignore, and neglect” is the meaning of “hate” in this verse, because “hate” in the first phrase is juxtaposed with “not choose” in the second phrase. The “they” in the phrase “they hated knowledge” refers to the naïve ones, the mockers, and the fools (Prov. 1:22). The naïve ones “loved” their naivety, that is, they chose it over knowledge, and the mockers did the same thing by “delighting” in their mocking. Meanwhile, the fools “hated” knowledge, that is, they chose ignorance over knowledge.
There is no need to be naïve, a mocker, or foolish. As we see in Proverbs 1:31-32, that kind of stupid behavior only results in trouble, and can lead to death and destruction—dying in this life and everlasting death instead of everlasting life in the age to come. God says, “Today I call heaven and earth to be witnesses against you, that I have set before you life and death, the blessing and the curse; therefore choose life, that you may live” (Deut. 30:19). We humans have the freedom of will to choose life or death, and the wise person chooses life.
[For more on the biblical use of “hate,” see commentary on Proverbs 1:22, esp. definition 4.]