[lhorie]

Not doing anything about CSS isn't separation of concerns, it's just a leaky abstraction. Separation of concerns implies some work was done to achieve some level of decoupling that would otherwise be tighter.

In fact, the criticism that react components can have style clashes is precisely one of not having enough separation of concerns. The fact that there are numerous libraries to address that deficiency further indicates that react as a platform is severely affected by the underlying level of abstraction when it comes to styling.

It's fine to defend a technology you like but calling a weakness a strength does nobody any favors.