That could be said for any investigative technique. Simpletons said the same about CCTV but now no sane person would deny the benefits of video surveillance. It *works*. It helps *reducing crime*. Those are cold facts. We need to slay that last sacred cow and make another step towards a safer society. And it will happen, whether you want it or not.
I'm not arguing against DNA testing, moron. I'm arguing against compulsory collection of DNA samples from every resident of the country as the OP claimed that there was "absolutely no reason whatsoever to oppose this." If you want to compare to CCTV, that would be equivalent to requiring every resident to have a camera recording their movements 24/7.
If the governments had the courage to do it, every citizen or resident of the country should be compelled to give DNA samples. There is absolutely no reason whatsoever for any ordinary citizen to protest or oppose this. Indeed any opposition should be viewed as a reason for suspicion.
Because of course there is absolutely no chance for abuse, such as DNA planting, or error, such as cross-contamination.
Thus spake the master programmer: "After three days without programming, life becomes meaningless." -- Geoffrey James, "The Tao of Programming"