Mr Bubbles
Superstar
She is pretty but she was never the prettiest or best actress on any show she was on. She has no body and it was said back in the day that she was the reason her show go canceled.
was not willing to sleep with the right dudes
Everything was set up for her to take over in 2013, but Ariana slid in that lane and broke through like the Wu, unexpectedly.
Even when she was on Victorious, she wasn't the best at anything. She wasn't the best actor, she wasn't the best singer, she didn't have the best character. She was the straight man and she did well in that role, but there's a reason she didn't blow up. The most memorable song from that show ("Give It Up") wasn't even hers.
She was the prettiest though and that usually is sufficient.
I think the earlier responses about her not sleeping with the right guys is the answer. If the Weinstein thing showed us anything it was about how sleeping your way to the top in Hollywood is a very real thing.