On Mac there is the possibility to open a new project with Cmd-O.
In my case this interferes with another command (Cmd-I – sorry, I do not remember if this is the standard) so when acting a bit erratic my project is closed. A nice kind of Game over, but very often happening when undesired (well, I could change the shortcut, but Cmd-O is a kind of standard for many apps).
Beside all this above: Wouldn't it anyway be more logical to set a prompt „Do you really want to open a new project?“ resp. „Do you really want to close this and open a new project?“, the same as when closing CT?