Every day dozens of files are checked by the moderators in their own spare time to make sure that they are correct, not offensive and not a duplicate of existing files. Additionally a screenshot is made to have the nice little picture for all to see. Despite their hard work we still have a backlog of files. Do you really suggest that they should be translating submissions as well?
The rules are simple and stated when you submit a file, if all did that the backlog could be smaller; so descriptions in English and ensure that the file has not been submitted before.
And don't make this about Americans either. A fair amount of the mods is not American and all agree with the policy as stated.
If we allow descriptions in any language it will become a mess. Most of us will recognize German and know what dictionary to use, but what about other languages? Whether you like it or not, English is the language understood by most of the users here and is the official language for this site. If you really only want to use your local language try to find a site like this in German or the language you prefer.