&quot;You lack key knowledge&quot; is already an order of magnitude less name-calley than &quot;You are ignorant&quot;, because it doesn&#x27;t take the form &quot;You are X&quot;. But why diminish the other person at all? Build them up by increasing their knowledge.<p>The distinction here is simple. Factual comments about insurance and licensing: great for HN. Comments about people&#x27;s knowledge levels and getting tangled in personal bickering: bad for HN.