Ok, as the author of the question I will explain my motivation:
I would use "big-list" for any question that actually asks for several answers. I feel that "little lists" are an automatic result of questions that ask for a single answer, anyway.
Note that the point of big-list is that people who think that list questions are counter to the idea of Stackexchange can ignore it. So it should be used on any question that runs counter to the "single answer"-rule. It does not indicate that I want "as many answers as possible".
I don't think that this is too subjective for dictionaries.
It is quite obvious that one wants no errors, comprehensiveness and additional features like pronunciation, conjugation or dialects. It is exactly the presence of the extra features that makes this a list question in the first place.
Well, yes, I could have accepted my own answer with the Austrian dialect site and pulled it to the top, but this is a critique on the software and not on the fact that I accepted the highest-voted answer. And I can accept strange answers on non-CW questions as well and pull them to the top.
(And BTW, the critique on the software will lead nowhere because they will hardly change it for the few CW questions.)
The way the software is implemented does not just make it possible to accept an answer, it has consequences not to accept an answer: It will make the question float to the front page again and again.
I have to say that I do not understand that "people will not read on if there is an accepted answer"-issue. Well, if they are searching for a dialect dictionary, it is their own fault if they don't read on after LEO. And if they are just searching for a dictionary the accepted and the second-voted answers are just fine.
In addition, accepted answers can be switched, so this does not mean that you or I now write the cool summary answer and it will always stay below the accepted answer. You can even copy it into the accepted answer if you don't trust me to switch my accepted vote, but this would be ridiculous at the moment.