From time to time someone posts something that may just be a youtuber advertising, or it is outright spam, in some cases it might be phishing. What I often see is that the spammer gets banned fairly quickly ... but their post, with the information that they want to get out there, remains!
Mission accomplished. That guy from India already made his pitch. Banning him is somewhat irrelevant.
His pitch, and all of his contact info from phone to e-mail is still intact. By not taking that down, he has essentially won the game, and (I see we keep getting spam from India) will just burn off another account the next thing he wants to post.
Since one of the things spammers do is leave their contact info embedded in a post, possibly using things like "DOT" or (at) to make their information a little bit harder to filter, couldn't the mods just delete everything with a --- snip --- and "advertising is not permitted"?