Well, some people just like to hate for no reason. Once you’re successful, a lot of people crawl out of their holes JUST to hate on whatever that person is doing. It’s okay to have an opinion but it’s not okay to slut-shame someone. You can disagree with what Ariana wears just like you can support her dress decisions. She is 21. She is living her dream and nobody has the right to make it look like a bad thing. Besides, why would you care about what she’s wearing? Does that affect anyone’s life? I love her but what she wears does not affect my life in any way? So why should it matter to people who aren’t fans? Sure, you can say that you don’t like it but there’s no need to call her names or, worse, to say that she doesn’t has talent! For me that’s the worst. I understand that not everyone likes the sound of her voice just like I don’t like the sound of some artist’s voice BUT that doesn’t mean that they are not talented.
On this note; give your opinion on whatever you like (without being a complete asshole) but let people, famous or not, live their life the way they think is right. As long as they’re not harming you there’s no need for you to harm them.