Worf has a serious chip on his shoulder whenever it comes to Klingons not living the Klingon way. After all, he didn't have the benefit of a Klingon upbringing, he was mostly raised by humans, and has been overcompensating ever since. That especially showed when it came to raising his son. Though he's a hypocrite because he first shipped him to his human parents before raising him himself. Then it was Klingon warrior this, Klingon warrior that.
Then Worf sees Alexander years later actually trying to be a Klingon warrior, and he gets annoyed all over again. Worf's an 'interesting' character.