Why won't my parents let me play fortnite

User Rating: 10 | Fortnite PS4
Hi, my name is will and I'm 13 almost 14 and I just got a ps4. As soon as I got I downloaded fortnite ( with my parents permission). I played it with my friends and by myself for a day. Then my mom came down stairs and saw me playing it and freaked out. (My dad was just sitting on the couch). And when my got upset that I was playing it my dad did as well. I just want them to let me play. I used to play tf2,csgo,saints row, and other stuff on my computer. That was a couple years ago because it broke. They didn't let me play them in the first place. So when it broke I just had to use my phone and watch YouTube and stuff. I told my mom I wanted a ps4 and she said that it was better than watching bad shows. I showed her what I game I wanted and she and my dad said it was fine. Seriously can someone help