Someone once said that he and badspot started to hate eachother; badspot fired em, then ephi took his anger out on the BLers by destroying RTB.
I sincerely doubt that Ephi got so petty as to shut down RTB solely out of spite.
He was done with working on RTB and dealing with the Blockland Forums and he left.
It cost a fair amount of money to host RTB, and he wasn't going to hang around here anymore, so it made no sense for him to continue to foot the bill for something he wasn't going to have anything to do with.
And I imagine there was no one in the community that he knew of, who he could trust to be able to both look after/improve/run RTB AND afford to host it all, as well as wanting to do all of that.