Because manual day trading requires intense focus. You cant easily trade profitably and run a chat room at the same time. It will be distracting and you will lose focus for sure.
They do have helpers that explain some trades and add commentary. While the main trader also gets help/tips from users about which companies just announced something or are on the move. Even the best trader can’t be aware of everything going on, but once alerted they can take a quick look at a chart and decide to get into the trade.