Malte,
if we are talking about translations AS content rather than
translation OF content, you are certainly right.
In a class dealing with the critical edition of some French
thinker, for instance, the user should not be automatically
directed to, say, the English translation because his UI
locale is German and, because of the missing German
translation, the default of English becomes active.
Instead, they should be offered all translation items with
all available genesis information.
In contrast, the translations of educational texts of some
arbitrary knowledge domain, should not be allowed to be
so bad that the source needs to be consulted, and some
content management approval procedure would probably
guarantee this quality. Therefore it makes sense to
automatically suggest a translation without bothering the
user with too much choice.