How is anybody pro abortion?

An abortion is by nature an unwanted pregnancy. It’s a mistake. A fuck up. Often, but not always, resulting from being irresponsible

Further you look at the statistics of whom gets abortions, the demographics, etc and its not pretty.

Children tend to be like their parents, and grow up often becoming products of how they are raised, along with their environment.

Thus, how does a logical and rational person oppose abortion given it is simply limiting potential future populations that resemble the parents?