I think not. Everybody's already used to the idea that there could very well be other kinds of life out there, whether from scientific ideas or from myths and fairy tales which could just as easily incorporate aliens as spirits in the sky, so it wouldn't be a big deal even to people from low-tech societies who don't think the way we do or get exposed to the same facts and ideas that we do.
And if no life were found, then we'd just have found out that there are a bunch of lifeless planets and other stars out there, which, again, is something we're already used to.
Some would be thrilled to find out that it's possible to explore and travel like that, but others wouldn't care because of the lack of practical real-world effects on our lives, and unless a threat to us here at home were discovered, nobody would think it was a bad thing.
