Why do people got to judge us young moms so harsh?

I am a teenage mother.(15) It was very unplanned. I used to be so immature and stupid back then, didn't know who I was, trying to be someone I wasn't to fit in. Then I got pregnant and that all changed. I decided on finishing high-school online ( homeschool) and got a job at the church's nursery. ( they pay me). I am not on welfare or helped by the state. I plan on finishing highschool and going to college( parents are paying for it) then trying to get scholarship money so I can pay for medical school to become a doctor. I changed and grew up. I gave up being a carefree teenager and jumped into basically a real world. I am accountable to my son and love him to death. I would do anything for this little boy. I am a good mom I know. And thanks to family, friends, and 4500 dollars I had been saving up for years I was able to afford everything my baby needed without having to burden my parents financially. But still people still bash me. Saying I am too young. Saying I should have given him up for adoption. It's not just me. It ALL teen mothers. People don't think they can do it, and one think that frustrates me is they call us s and sluts. Not all of us are s you know. We make mistakes, we are human. We lose our way and make BAD decisions. But at least we take responsibility, grow up, and learn from out mistakes and move forward and start doing right. ( well some of us because there are some bad teen moms but there are bad older moms too). don't you think people judge us too harshly? I feel like they do. & Though I don't care when people call me names, I feel like I don't deserve that. & my son doesn't deserve to be called a mistake.