Facebook Flux: simplify the dataflow

An overview of Flux by Facebook.

Flux is the application architecture that Facebook uses for building client-side web applications. It complements React's composable view components by utilizing a unidirectional data flow. It's more of a pattern rather than a formal framework, and you can start using Flux immediately without a lot of new code.

What I'd personally really like to learn from people here on LtU is: What do you think should be make simple, possibly at the expense of other concerns? Apparently Flux is saying keeping dataflow as a unidirectional loop is an important thing for various reasons, presumably including mental modeling of it all. Are there other things you'd say are more important? Or do you have a language+environment such that nothing has to be simplified and kept simple, and yet still stays sane for regular developers to grok? (Other things that I think have a meme along these lines: DCI tries to eschew polymorphism; DDD tries to keep close to the business domain; Go developers refuse to add things other languages have; etc.)