There are several measurable differences between cells and viruses.

Defining what viruses are, and thus whether or not they're considered "life", is quite scientifically important. We need to define things based on what their uses and limitations are. Viruses are already known to have unique characteristics; if we further define those characteristics and are able to distinguish them from organisms, we can potentially discover new things about life, or new things about almost-life as a whole that fits certain parameters. We dont know what we don't know. Everyone freaking out over labels is missing the point, as usual.