I mean people like what they like, also I'd say "learn another language" makes more sense for 3.X where there were a ton of good language options. C# isn't the only thing up-in-the-air due to 4.0's binding system change (that will hopefully be worth it), though C# will get priority for an obvious (and understandable) reason while other bindings will need people in the community to create new efforts for each language that still doesn't have an option.
I say that as someone waiting on Nim-lang bindings (and 1 person working on them is consistently working on it) for 4.X (the 3.X bindings were listed as production ready here). I mean unless there are other languages that also: 1. are usable outside of Godot 2. Have an easily-readable style 3. Have good performance 4. Have (optional) low-level capability/options/flexibility. (I've never actually looked at C# but I don't think I want that ecosystem/setup)
Which, from what I've seen seems unlikely as most things seem to pick a side when it comes to speed/capability or ease. Maybe there's an option with some form of compiled Python but that seems to be a technical mess to get through/decide on and even then said option wrecks its compatibility with Python Godot bindings because obviously it's not interpreted Python anymore.