It's great that you're providing a stable home, however that's the exception for unwed parents. Typically, the father wanders off and provides no support. None of the mother's options at that point are as good as a stable marriage/long-term relationship with the kid's father.

That's how the statistics work out. We can argue about why that happens, but it's absurd to suggest that it doesn't.

Parents' choices, and having kids is almost always a choice, have consequences.