Because a warning isn't going to act as a deterrent so SE has to go stronger with a 10 day ban. They've been warning people for years. But streamers and content creators especially in the past year or two have been egregiously thumbing their nose openly at SE's rules. SE's policy of not being heavy handed has been a good compromise but with people constantly questioning why streamers got allowed with openly using these tools, they forced SE into a heavier handed position. People are still going to use these tools and SE knows it. But hopefully they will go back to being more discreet so SE and the player base can go back to the ceasefire they had about the issue.