Upvote:-2
For most cases of most countries, having a citizenship of a country grants you privileges. If you are a citizen of country A and country A citizens don't need a visa, then you don't need a visa, whether or not you are also a citizen of country B.
However with the US and Syrian citizenship it's different. Syrian citizens are subject to restrictions, and those restrictions apply whether or not you are also a citizen of another country. The visa processing officer treated you absolutely correctly and according to the law.
There isn't a law saying "treat Syrian citizens as if they weren't dual", it just says "Syrian citizens are subject to these restrictions..." and those restrictions apply regardless of other citizenships. You are a Syrian citizen, so the restrictions apply to you.