On the one hand, there is some truth in it that labels can divide. But on the other hand a lable is just a shortcut. Shortcuts are undeniable important to communication: If you think about the word "ball" you might visualize something completely different than I do. Nevertheless the invention of words (and labels) is very helpful, we could not communicate efficiently without them.
Discussion
Yes we need a common language and any word in itself is a label for something but you and I both know that is not what I’m talking about.
Labels, even seemingly harmless ones can be very harmful. Just calling yourself X limits your mindset to the individual that typically represents X. At other times giving yourself a political label positions you to think within the boundary of the group and the typical opinions held by people who identify as that label.