>1) Some of these subreddits may have contained CP, the illegal ones were being actively removed by admins.
CP was posted in the same subreddits. The admins were tired of spending their time determining if reported images were illegal or not.
>2) Calling pictures of 16-year-olds in bikinis CP is not very useful and dilutes the term.
A 16 year old in their swimsuit at the beach isn't CP. A 16 year old posed in their swimsuit like a porn star in a bedroom is CP. The latter is what was posted in these subreddits.
This isn't an issue with unfair application of sex offender laws or the vilification of accused sex offenders. This is Something Awful forum members forcing reddit admins to finally remove at best objectionable content, at worst illegal material.