[vvanders]

For something engineered, sure.

However if you're working with designers who don't have a lot of formal education it's much easier to convey the concept of a function that "pauses" where yield() happens.

Also quite a bit of gameplay code ends up as throw-away so being able to quickly put behaviors together is a plus.

[striking]

You're saying a tree of FSM states is more difficult to convey than linearized coroutine code, with emphasis on informal programmers/designers?

You may want to take a look at visual FSM solutions, which do what you specify and more, easily.

You're not even wrong.

https://unity3d.com/learn/tutorials/modules/beginner/animati..., for an example in an Animation program