I admit, the feeders probably wouldn't be so inviting if they weren't on the edge of a small wooded area in our yard. I don't worry so much about the squirrels anymore. I have the feeders there because our area is heavy with hawks, and they target the feeder birds. Often, I see a pile of feathers in the yard from one poor bird that got caught. I've even stopped an attack, running towards a hawk when it attacked a bird. The trees give the birds safe ... or safer cover. I have 4 feeders. On a positive note, when there aren't any birds at them and not a bird to be seen, I know there's a hawk nearby.
I don't mind bringing them in every evening, although I might trim them back to 3 feeders instead of 4.