You didn't include a "well if they're not citizens..." statement although the same could be true. They could very well not be US citizens, some of them at least. But you quickly dismissed the idea that any of them were without a second thought. And for good reason, they're likely not.
The undertone of your response (and frankly continued persistence to defend it) is imbued with a sentiment that only furthers the divide building in the USA. Among the rising tide of antisemitism, anti-Isreal, or Pro-Palestine ideas, there's also the notion that being Muslim or supporting Muslims is un-American. You may not realize it, but that qualifier, "if they're not citizens", when talking about college kids who are more than likely US citizens is sewing an idea that these aren't Americans with the same rights "we" Americans have. If we're discussing the norm, there's no need for qualifiers...unless you think there's a deviation from the norm.