I do not understand the all the negativity behind the single-window mode, especially when it is an optional component and is not "forced upon" users without an alternative, save for using an older version for as long as it works and is maintained, waiting for or working on a fork, accepting the changes, or abandoning ship and seeking an alternative.
As a user of a keyboard-driven tiling window manager that does not completely follow the WIMP model, I find the option of using a single window mode to be a welcome change.