Translation:Except for her, all of the other people came.
Why is the "除了... 以外" sentence format no longer being used? When I started learning Chinese 30 years ago, that format was practically gospel: if your sentence started with 除了, you needed to have 以外 after the thing that was being excepted. Is it now becoming old-fashioned to include "以外", or perhaps it's just dropped in informal conversation?
Because those "bookends" have gone out of fashion?
The pattern 除了... (以外), ...都... expresses "except." Note the 都 (dōu)! (cf. 每...都)
The pattern 除了⋯⋯ (以外), Subj. + 也/还⋯⋯ expresses "in addition." Note the position of the 也 or 还!
以外 is optional. Omitting it does not change the meaning.
The current English isn't technically correct. It should be "All of the people came except for her" or something like "All of the other people came but she didn't".
Because "she" is not part of the "other people", who didn't come, so she's not an exception to them.
I might not be wording this clearly, so let me know if you do or don't understand what I'm trying to say.
Someone said in another post somewhere in this lesson that the former is more of an "out-group" other and the latter is more of an "in-group" other. I assume an in-group is more like friends and well-known other people but it was not explained what the subtle difference really was. Maybe the out-group is unspecified other people. Or maybe there is no real difference. I really don't know.
The use of the accusative "her" in this translation shows gross grammatical ignorance. It might be acceptable usage in a backyard BBQ or in pub when "tradies" gather at 4 PM. If "she" is foreign to you and you know only "her", then you should amend the translation to read " Except for her, all the other people came." If you stubbornly insist on your preferred syntax, then you should rewrite as follows : " All other people came except SHE." All other people came but SHE - and not "her" - didn't come. Consult any "Grammar Made Easy" books.
I am a linguist and an English teacher. Sorry to tell you this, but you are wrong. After prepositions, we cannot use the nominative case. "Her" is the only correct grammatical form that we may use there. And don't be so mean! How dare you be such a mean person to that language learner.