Bad Mojo Undeserved?

Let me begin by explaining that I respect, and like Crows. I admire their intelligence. But it is clear to me that my backyard songbirds do not care for these comparatively enormous Corvids one bit. I had the opportunity to do some work at home yesterday and from time to time monitored activity at the main station. I expected trouble from the squirrels. In fact, the squirrel count was stunningly low (two visits, period.) but so was the bird traffic count. And it was a few hours before I identified the potential cause. Two American Crows (likely a breeding pair) were perched in full view of the feeders. They stayed around for some hours, and only after they left did I see Passerines again. Now, what I have previously read Crows are not considered important predators to songbirds. But was their presence unsettling? I can only keep watching and learning. Maybe I am connecting the wrong dots.