Hating what you want to become

Today on the Thoughts and Money session with Brooke, she mentioned that if you hate people who are wealthy, you will not be able to become one. But she stated it more generally, and I was thinking about how I have negative judgements about wealthy people AND skinny people, so I need to work on my thoughts!

Can you expand on this concept, and provide some insights as to where to start in addressing negative thinking like this?