Anyone's posts should be removed regardless of rank if they're against the guidelines. But I think the amount of people who report it also plays a factor of what gets removed or not. Next time just bring it up to a mod or admin if you need to.
You should absolutely report anyone that violates the community guidelines regardless of their ranking and there's no different measure that is used for judging higher ranked members. Our posts or questions can get removed too. Just remember that moderators are human too. We do sometimes remove things by error and then the final decision lies with the admin.
Because a lot of people have low self-esteem and haven't achieved much in their life so having a rank hehe they feel important and superior not realising every person on GaG can achieve the same rank if they choose to. It's nothing to be proud of. I was friends with a mod one who left. He was so arrogant he said he loved removing posts and he was proud of it. He was one of the most deceitful , manipulative gagers so I cut contact with him. He was manipulating me to send nudes.
Your definition of rude may not be anything like someone else's. And being polite is not a requirement on G@G. But there are a whole lot of requirements that posts must meet that may have been violated causing a post to be removed. So it is likely that the ones that hurt your feelings are perfectly legitimate, while the ones you did not find rude broke specific rules.