Why are my parents so protective?

i feel like my parents are too protective, or maybe too strict. i have two older sisters that are eighteen and ninteteen years old. im only thirteen so i dont have much to rebel against for them being strict to ME. but to my sisters, they just trap them inside the house. they do go to college, and they do have jobs, but other than that, theyll be at home. my sisters always get invited to go out with their friends, but my parents just seem to get frustrated for a reason i dont know. i get a little scared because my parents just keep babying my sisters and one of them is turning twenty next year. twenty! and theyre curfews are at 8-10:00 and they can only go out for what seems like once a month. other than them getting frustrated and avoiding them to go out, they have dating issues too. my sisters arent allowed to date at all. i dont know why, because you cant avoid love. is it because we are of filipino heritage? idk. because if thats the reason, they should adapt to american ways. my sister went out with one of her guy friends, and she said she'll be home at eleven, my parents were mad, and she came home around 1 because of the parking. her guy friend walked her to the door, my mom saw the guy, and got mad. overall i feel we're different than other families because my parents just have different outlooks in a typical teenage life, and with their rules. i just base this by comparing it to other families. im pretty sure a person gets their curfew later and later as they grow up. how should my sisters approach this nicely into a conversation with my parents in at least giving them a little more freedom. thanks to your answers! :) tips, advice, suggestions, stories, anything! thanks!