The blue highlight on CodeMirror showing the cursor location can be distracting and annoying for some users.
I tried to find a balance between wikitext in articles and complex markup in templates. I think the best solution is to make several themes and allow skilled users to use own styles (from User:username/common.css), also active line highlighting (and other features) may be enabled/disabled by users.
May be should create a new task for discuss these features. Seems for now, we make the view less aggressive and unusual for users for soft launching and getting feedback.
I think this is reasonable enough :-)
P.S. found T95148