It's like if someone is killing a lady in the street and you say "I don't make any $ from it so I won't call the police"
Coinmarketcap cares about these types of altcoins but as you can guess they can't monitor all coins daily and without people reporting it can take a while before the coin is flagged.
On all numbers of coins listed on CMC they wont really able to detect or monitor same as you said.Therefore, with this matter i dont really care at all if its listed or removed.
You can check anytime on your own discretion if you have doubts on the said altcoin and lastly relying into these preference site isnt reliable anytime.