I think your answer boils down to "pick the right tool for the job". Of course state machines are cumbersome for systems with loads of different states and tran

I think your answer boils down to "pick the right tool for the job". Of course state machines are cumbersome for systems with loads of different states and transitions. But state machines are really useful when designing safety-critical systemsfor aeronautical, automotive or train components, especially if one uses timed automata for modelling. It's possible to either generate the code from the model or use the model to automatically generate a complete test suite for the modelled system. Very useful for verification purposes.