[I have been told that it is difficult to focus with an aperture of f/1.4.][1]

So, in which kind of scenes does it *actually* make sense to use the f/1.4?

In portraits they say that it is important to keep focus on both eyes (ruling off f/1.4).  
In moving subjects (street photography) it s simply not possible to focus with f/1.4.  
In food photos it will then focus only a particle of food.

What are the *PRACTICAL* uses of f/1.4?


  [1]: http://photo.stackexchange.com/questions/20344/is-it-difficult-to-focus-on-1-4f-prime-lens-and-if-it-is-how-to-counter-that