Why do people seem to respect someone that gets angry and calls people out on their BS than someone that’s too nice and a pushover?

My female best friend is a kindhearted person. Very genuine, always there for us and honest, but when you push her limit, she doesn’t play. You don’t wanna push her button because she doesn’t put up with anybody BS. When someone disrespects her or talks to her any kind of way, she doesn’t back down without a fight. A lot of people respect her. My guy best friend is the same way.
But for me I am a kindhearted person and very nice person but I get the opposite of what they get. I get pushed around, people just can’t talk to me whatever way they want. I act so nice and try to make everyone happy. I got yelled at by some people because they expect me to help since I’m a very nice person and never get angry or speak out. Why don’t I get respect like my best friends do? When I try to stand up for myself, I get laugh at and get told to shut up.
People expect me to be the helping hand and expect more from me. My best friends said I’m not going to get respect that way and I don’t have the hands to fight at all. Nobody believes be when I said I’m going to get into a fight. My dad even said, “No you not! You’re just going to let people push you around like you always do. Don’t you say that because you won’t do nothing. You’re way too easy and you need to start being an “asshole”. Quit being so weak! You’re being very WEAK.” And he got into my face.