I'm not even remotely in the author's situation, but who hasn't sometimes resented some aspect of how they came to be? To which my own response is always "but that's what produced me! If anything had gone differently in even the minutest way (like which of those wiggly things wins the race) I wouldn't be here! Someone else would be. Case closed.
From personal experience, it’s rare that someone in this position resents how they came to be but rather how parental figures in their lives handle this information, purposefully withholding it from the party that had no say in the matter yet means the most to.