“are punished.” The Hebrew word is anash (#06064 עָנַשׁ), and it means to be punished, or to be fined (cp. HCSB, KJV; NASB, YLT). In this instance it is a synecdoche of the species, where a fine or punishment is a specific penalty put for the more general penalty: they will pay the penalty or “suffer for it.” Some modern versions simply omit the synecdoche for ease of reading. For example, the NIV84 says, “but the simple keep going and suffer for it” (the NIV2011 says, “pay the penalty”). The NLT, a more paraphrased version, reads, “The simpleton goes blindly on and suffers the consequences.”
There are times in life when it is wise not to confront evil, but instead to avoid it. It takes experience and walking by the spirit of God to consistently make the right decision as to what to do. There are clearly times when evil should be confronted and dealt with, and there are other times when it is best to avoid evil; to hide from it and “fly below the radar” as we say.