This is a formal, written-style expression used to say that something does not reach the level of being worth a certain action or feeling. It literally means 'does not hit the mark of ~', so it implies that the reaction would be exaggerated or misplaced. You often see it with words like 驚く (to be surprised), 心配する (to worry), 非難する (to criticize), or 感謝する (to thank). It is a way to reassure someone or dismiss a concern, but in a polite and logical way. For example, if someone apologizes profusely, you can say 謝るには当たらない, meaning 'there's no need to apologize.' The nuance is that the situation is not that serious. It is not used in casual conversation; it sounds like something from a news article, a formal speech, or a business setting. In speech, you might say そんなに心配することはない instead. Note that the negative form には当たらない is the standard pattern; the affirmative には当たる is rare and has a different meaning (to be worthy of ~), so don't mix them up.