W3itch.io apparently decided the best way to accomplish their goal would be to not only steal itch.io's site design, but the source code itself. The games hosted on the website were also taken without the consent from their creators.
After being called out by the KennyNL Twitter account, W3itch.io admitted to stealing the CSS, as well as buying Twitter followers. However, they refused to take the website down, and seemed to claim they were unable to remove listings of stolen games.