They don't read literally everyone's private communications. The vast, vast majority of collected data is discarded without having ever been read. Only where it's relevant to national security are analysts permitted to actually read it.
It's very naive to think that targeted surveillance, and the means to achieve it via bulk collection and other methods, isn't necessary in the incredibly hostile world in which we live.
Please put away your dogmatic, child-like slogans and open your eyes to see the real world.