People who have 11 and 12 on farm probably didn ' t do so via pugs , and probably aren ' t doing it outside of their statics . <| sep |> D ' ailleurs les gens bossent mieux quand ils se sentent bien . C ' est d ' ailleurs pour cela que l ' on voit que l ' open space s ' impose de plus en plus c ' est bien parce que a favorise le bien tre des gens . C ' est pas nouveau y ' a pas mal d ' employs qui se font chouchouter afin qu ' ils restent dans leurs boite . Des chouchous il y en a partout et il y en aura tout le temps . Ce n ' est en rien reprsentatif d ' une envie de l ' entreprise de s ' impliquer dans le bien tre de ses collaborateurs . <| sep |> That isn ' t a cargocult rule , it has a real impact on how easy it is to use library functions . Imagine LINQ if you had to have a different . Where function for every type of collection . Speaking of which , LINQ mitigates the performance problem by including a type check that will downcast into ListT when applicable . That way you get good performance when needed , but without losing the flexibility of accepting an interface . You can also choose to offer two versions of a function , one with the generic interface and one that is more specific . This is why that rule is part of the . NET Framework Design Guidelines . P . S . I do think the always return an IList or an IEnumerable rule some people use is bullshit . But that doesn ' t have any of the advantages listed above .