I've seen write-only Java where the design was fragmented over so many classes that nobody could really make a meaningful design change anymore. Classes with dozens of methods, gross violations of SOLID principles, etc. It seems entirely possible to do the same in C#.

That being said, languages in that space seem generally less prone to write-only code, so I'd agree that language choice has a big impact. Especially when an entirely novel language or framework enters the picture.