The moderators are not online 24/7. When online, not every problem post may be seen due to the high # of posts.
Should you have an issue with a post not meeting the rules please use the "report" function to flag the post for review. This is the small yellow triangle with the exclamation mark located next to the edit button. When you flag a post it lets us know where to look so that we can deal with it.
If you don't flag a post with a personal attack it may not be dealt with in a timely matter or at all because it may not be noticed. If you don't bring it to our attention don't complain about inaction or bias.
ETA: When a post is flagged it sends an automated notification to mods and shades the post so we can find it easier. Thanks for testing it Mac.