It is ...
There was some suggestions, like give Tief-Rogue a limitation "once per turn" to all Bonus Action ... well, Bonus Actions

... imho that would still help Tief-Rogue to feel better than some other classes, but it would be much more ballanced.
But as it seems from lack of any change, Larian likes it as it is.
Kinda odd imho that they dont allow us to Sneak Atttack by Bonus Action, as we should ...
But they let us Attack twice with Bonus Actions, as we shouldnt ...
Maybe there is some corelation? O_o