The term “pro-choice” came first. “Pro-life” was an attempt to not be portrayed as moralistic naysayers.
Our culture valorizes the inoffensive and anodyne, and whether we like it or not, this is anathema to moral principles...
Nevertheless, “pro-choice” is not an accurate term. It lacks context, as if “choice” includes picking the color of your shoes as morally equivalent to anything else you might choose to do.