I definitely consider it an overreaction to call the described approach over-engineering. Separating simulation and presentation in to separate threads is commo

I definitely consider it an overreaction to call the described approach over-engineering. Separating simulation and presentation in to separate threads is common and very practical in many games (2d or 3d). It is also common and easy to support a single threaded mode that just runs both simulation and presentation update from one thread. The single threaded mode can make debugging certain issues much easier, but it is rare to have a desire to ship single threaded.