Why do parents push their kids about their grades?

My dad is very strict about school so is his girlfriend so when I get a bad grade, they call me out on it and give me crap about it. I feel like my dad pushes me too much. He would say, “Come on now! You can’t keep failing your classes! You have no excuses. It isn’t good enough and you keep failing, you will NEVER get your high school diploma. Not even near it! That’s the truth!” Right in my face. I wish my dad wasn’t so blunt. 😭
Giving me lectures and pushing me to do harder which that’s is true but I’m not a straight A student. Please don’t say “Your parents wants what’s best for you.” Or “Your parents love and care about you.” Pushing your kids and cussing them out about their grades doesn’t sound like love. It’s slave labor. 🙄