On the contrary. Like minds attract - unlike minds repel. Gaydar is a feeling of disgust, or a sense of abnormality - something is "odd."
Only those who are homo would not see it. They would resonate with it. To them, everything would appear "normal."
So, what was that you were saying about a closet?
A gay co-worker once told me my GAYDAR was better than his. I even demonstrated my ability at a fast food place once, then the guy started talking and my friend went.. OMG! LOL