Why is my mom such a prick?

Ohkay, so I got this really nice haircut that me and my sister think look really nice, while my mom and dad are constantly bringing me down about it saying it looks 'horrible' and 'horendous' and I might as well just go get it done again. Yeah there some flaws but I honestly think it looks good. Ugh what do I do about my mom, then she says that she'll take me to go get it fixed. And then I'm like nah I like it. Then my dad says what! Noo I don't care if you like it or not were goin to go get it fixed. Seriously like what the hell! I'm a teenager I can make my own decisions ugh