I don't know the reason why gamblers are not chatting on the Betfury site, but it's funny that there are more messages in the chat from admins than from users. By the way, I will not be surprised if this indicator is showing the total amount of users per last 24 hours, not the current online.
It's pretty common. Most probably AFK or playing without chatting.
That's why some would speculate bots when the opposite is true.