I'm pretty sure it's just that sometimes CS mods look through that stuff, other times it's people reporting your links if they find them to be not friendly to the CS Rules.
If you read the actual
post on why DNI lists are banned, you'd know, lol.
But tl;dr,
All of these are ripped straight from the post, most are paraphrased.
1: DNI lists often contain inappropriate content
They don't want young kids seeing a DNI list and then wondering "What's that?" and googling it.
2: DNI lists mention (often specific) criminals
3: DNI lists endanger users by giving a comprehensive list of all the things that would upset, trigger, or harm that user.
4: DNI lists are hard to enforce on CS as they generally focus on who is sending the content rather than the actual content being sent. It's also hard to limit what would or would not be allowed on DNI lists and no ruleset would completely cover everything.
5: A rule-abiding, enforceable DNI list on CS would look like "DNI if your profile has images of spiders on it." But you'd still see someone's spider profile picture when scrolling through forums unless you disable those things in the
settings6: Use the block function for any user you do not want to interact with.
7. Users may still request that they not be sent trades with certain species of pets (such as spiders) in their trade rules, but this is not considered enforceable unless it is clear that a user is violating your boundary intentionally. (I.E. 1 accidental spider in a trade with lots of pets vs 1 spider or lots of spiders in a trade spammed repeatedly)