To be honest I cannot abide bullying, and that what this is. She is no different to hundreds of other wannabee pop stars that have had success in the past. The vast majority of POP stars over the last 2 decades have been average at best, which is why the music business is in such a horrendous state.
This girl is pretty and full of confidence. She's not dressed inappropriately which seems to be the trend these days, and she will probably be successful... and for her spirit I hope she is.
The whole likes and dislikes on YouTube should be done away with, If you don't like something, say nothing, just move on. If those who have commented can do better, then they should spend their time proving it, and not wasting their time being nasty and vindictive to others.