OK, this turned to be a very a long reply, because I wanted to take the proper time to articulate it, as I appreciated your words and your tone. Here’s a summary:
- All these use cases are relevant, but they are not hindered by Compact Language Links, at least for most readers.
- Logged-in users, who have advanced needs about languages and who feel that this is inconvenient can disable the feature.
- Your suggestions towards the end are valid, though probably only useful for some particular groups of users. I filed them as a feature suggestion to explore later.
For all of the use cases in the first paragraph—the languages are all accessible. I agree with you when you say “Interwiki links are a fantastic source for this.” This is why they are just compacted, certainly not limited.
Moreover, for most people they are more accessible. Let me explain why. We can compare three ways of showing interlanguage links, and this is backed by data:
- Showing them as they are now: the whole list immediately when the article is opened.
- Compact Language Links: Showing them as a compact list of up to nine languages, with a button that shows the rest with a search box, in which you can search in your language.
- Hiding all of them until the user clicks a button to show the whole list.
If option #3 doesn’t sound familiar, it’s because it doesn’t exist any longer. It was used for several weeks in 2010. Analysis proved that showing no languages immediately when the page is loaded causes a ~75% drop in the number of clicks. This drew severe, and justified, criticism, and after several weeks the code was changed so that by default the whole list would be shown, with the option to collapse it. Later the option to collapse the whole list was removed completely.
At the same discussion that caused the reverting of the full collapsing feature in 2010, a proposal was made to show a compact list. Very briefly, the hypothesis was that not showing any languages initially makes it harder for readers to realize that any other languages are available at all, but showing a short list of languages makes the readers aware that some languages are available. It’s impossible to guess the perfect languages to show initially without any user input, but the point is not to guess them correctly; the point is to make the user aware that some other languages are available and to make it easier for the user to find the language they need.
In 2017 this is no longer a hypothesis. Now we know from the data that we collected that showing a compact list makes more people click on links. This applies to all the languages: "small" ones and "big" ones. All languages now receive more clicks, whether they are shown in the initial compact list or not. In some languages, the percent of people that clicked on language links went from ~0.3% to above 1% or even 2%. (FWIW data is open and everyone can freely analyze it again.)
So, of the three options above, we know that the one that option 3 is the worst, option 1 is in the middle, and option 2, the compact list, is the best, because it's the one that is the most convenient for millions of readers. We know this; it's not a guess, an impression, an opinion, or a hypothesis. It's data.
Hence, I am saying, that for most people the languages are not just accessible, but more accessible.
Of course, if you feel that this is less convenient for you, you don’t have to use it, which is why it is a preference that can be disabled.
Showing languages in alphabetical order is impossible because they are written in different alphabets. Showing all of them in German will make it possible to show them in alphabetical order and it will possibly be convenient to somebody who knows German, but it will make it completely unusable for people who don't. I filed this suggestion as a feature request, because clearly it will be useful for at least some people, for example the case for a German Wikipedia reader or editor that searches for images, or checks if the article is long or has sources.