Why does my Stepfather/stepfather's family/ hate me?

Okay, I'm going to start this off by saying that I need some clarification on how to deal with him and his parents, because frankly, this pisses me off. My mum married him a while ago, and frankly, I do like him, he's a decent guy, and it's been hard the past few years because he's a soldier, and it's been taking a toll on our little family. ANYWAYS, I've been smoking since I was 15 years old (yeah, I know, don't lecture me on it) and I've always dressed alternative, and have always had strong opinions on certain things like the government, law enforcement system, mainstream music these days, Education system ETC. I'm not an academically minded person and I want to peruse a career in music, but my Stepfather was the 'good, nerdy' type in high school, and with the way he 'governs' the family, I'm the square peg in amongst the cylinders. He doesn't like my taste in music, and flat out refused to lend me money AFTER I had cleaned the house up so I could buy a Dead Kennedy's CD, because he doesn't like the 'noise' I play. We got in to a fight over how I don't do well in school, and how I refuse to conform in a uniform public school (don't ask me how that works) And tossed my Doc Martens across the house, and yelled at me. and it's always been this way, and when he found out I smoked, he basically looked at me and said "Your a disappointment" And started shunning me all these years. I come home with my nose pierced, he yells and says it's 'not ethical' and that No one would hire me at a job with that piece of metal sticking out of my face (I then later got a call from a music store and had gotten hired, and acted a little smug) And then there's the grandparents, now, don't get me wrong, I love them, but the littlest brother gets all of their attention, they talk to him, and the last time I visited them they said a total of six words to me, then they got mad after I had told them that the milk they had was sour. I try my hardest to be nice to them and to not swear around them, but the last fight I had involved all of them, I said '**** off and stop telling me how to live my life' and I stormed out of the house, then later when I returned, they where talking about me and how I was 'wild'' and that I needed discipline. What the **** is their problem anyways? I'm going to talk the way I want to, I'm going to stick up for my beliefs and I'm going to live my life the way I want to, and I'm wondering why they can't just accept who I am and move on?