The problem is in how we perceive duality. The Universe contains everything and its opposite. The idea of the Tao is a balance of the opposing energies. Instead of one destroying the other, they are integrated into the whole.
Imagine a circle with a line drawn across its diameter. The top of the diameter is white, the bottom is black. If the background is white, you have half a circle. If the background is black, you get the same results. Is one part more a circle than the other part? Of course not, neither side is a circle without the other.
People should be looked at in the same manner, of course, they're more complex than a circle with two halves. The idea is to look at the person as a complete entity and realize they are human. They are not bad. They are not good. They are human.
This doesn't mean that one shouldn't dislike anyone. Some people deserve to be punched in the nose.
Here's a quote from the Merchant of Venice, a play by Shakespeare:
Hath not a Jew eyes? Hath not a Jew hands, organs
dimensions, senses, affections, passions; fed with
the same food, hurt with the same weapons,
subject to the same diseases, heal'd by the same means,
warm'd and cool'd by the same winter and summer
as a Christian is? If you prick us, do we not bleed?
If you tickle us, do we not laugh? If you poison us,
do we not die? And if you wrong us, shall we not revenge?