We have complaints at enwiki that the Single Edit Tab (SET) feature has gotten existing editors "stuck" in the wikitext editor. The pencil icon is too subtle, and there are no educational messages that point it out or provide any information about what to do when you previously used both editors, but your last editor pre-SET happened to be the wikitext editor.
We've heard similar complaints at mediawiki.org.
The visual editor provides new editors with a welcome box that has a prominent link to switch to the wikitext editor, plus education features that highlight links, Cite, etc. The visual editor offers existing, logged-in editors with both a dialog box to choose preferences and also educational features. But the wikitext editor offers editors nothing: no opportunity to switch upon opening and no information about how to switch if you wanted to do so.
**EDIT** by Elitre: Please help translate interface messages related to this change. Thanks!
Those are included in this small group:
https://translatewiki.net/w/i.php?title=Special:Translate&group=ext-visualeditor-ve-wmf&filter=%21translated&action=translate
Here's the specific list - in case you want to create them "manually", by replacing "en" with your language code:
https://translatewiki.net/wiki/MediaWiki:Visualeditor-welcomedialog-switch-ve/en
https://translatewiki.net/wiki/MediaWiki:visualeditor-welcomedialog-action/en
https://translatewiki.net/wiki/MediaWiki:visualeditor-welcomedialog-content/en
https://translatewiki.net/wiki/MediaWiki:visualeditor-welcomedialog-content-thanks/en
https://translatewiki.net/wiki/MediaWiki:visualeditor-welcomedialog-switch/en
https://translatewiki.net/wiki/MediaWiki:visualeditor-welcomedialog-title/en
If there's nothing to translate or you simply feel like walking an extra mile, please consider [[ https://meta.wikimedia.org/wiki/Technical_Collaboration/T133800 | translating the announcement on Meta ]], and post it on your wiki when it's fully translated ([[ http://www.timeanddate.com/worldclock/converted.html?iso=20160515T11&p1=339&p2=224 | or in 24 hours anyway ]]) on my behalf (you may need to tweak a few links when you post it on your wiki).
NB: If you are from a Single Edit Tab wiki, you want to [[ https://meta.wikimedia.org/wiki/Technical_Collaboration/T133800/SET | translate this message instead ]]. Thanks a lot.