Thats true. It will be futile to spend huge money for promotion if the reputation of the site is not good. Because gamblers are wise now to not risk their money on a shady site.
It's not that simple. 1xbit advertise their services across different platforms which is why they are still somehow attracting gamblers despite all the rising negative accusations against them over time.
Their bad reputation in Bitcointalk has definitely affected their business, but it isn't enough to shut it down completely.
Hence they should resolved first the past and current accusations against their site. If they manage to do so then there's a chance to for their casino to look different but I doubt if they even have plan to do that.
That will most likely never happen. They already tried coming up with different reasons(Changing teams etc) in order to improve their reputation here which clearly failed. It is pretty evident that they don't care anymore.