[spaetzleesser]

But a lot of them seem totally arbitrary and inelegant. CallerArgumentExpression requires a lot of attributes. CallerMemberName gives you the name of the caller but not the class name. This is hard to explain. It just seems random.

[guhidalg]

It's not hard to explain, it's a logical and small extension of other compiler-driven attributes. Just because you don't like it doesn't mean it's a bad change to the language.