Therefore, any site that wants to have things that are read by the largest set of people it aims for, should use English.
However, mixing up languages in one forum is just plain stupid. It's chaotic and it drives people away.
Now, if the ET had entire sub-forums for languages (i.e. all that you'd see on the frontpage was a link saying <discussions in language X>, linking to seperate forums (seperate diary lists, separate recommended lists, etc), then that would be fine.
However, with the way that ET is set up right now, using Scoop, using multiple languages is a really bad idea.
OTOH, the question was also raised of whether the largest set of people it aims for could not be reached by having diaries or threads in other European languages. The consensus seemed to be that we should try and see. That was the spirit of my diary. Since it was the first "other-language" diary, everyone had fun chipping in with all sorts of linguistic contributions, so it got multilingual out-of-hand. That doesn't reflect a prior intention to just have comments be posted in any language the commenter wished.
I'm very sorry to see the kind of reactions my diary produced.
I think what you mean to say is that it's in your opinion that's it's just plain stupid.
Speaking for myself, I wouldn't be driven away by a thread in Dutch. On the contrary, I'd enter it, and I'd try like hell to understand what is being said. Then I'd get help from a translation application, and once some bits and pieces would become clear, I'd start enjoying the thread with the satisfaction of a Sherlock Holmes who's just solved a puzzle.
That's for me ... I don't find mixing languages plain stupid and chaotic, I find it fun and challenging. In my opinion.