Part of it might be that it obfuscates the structure of the error message. Error messages, even without error cascading, and especially when taking a top-down approach to writing code, are long and meant to be skimmed. Human languages are great for reading top to bottom, but not so great for skimming. Terse (but not cryptic) formatted text, as found in programming languages, is much better for skimming.
You'll only ever actually read "As I infer types of values flowing through your program…" a few times while getting used to the compiler, after that you'll recognize it by shape and never read it again, and at that point all the anthropomorphized text is doing is taking up screen real estate that could have been used to display more errors.
You'll only ever actually read "As I infer types of values flowing through your program…" a few times while getting used to the compiler, after that you'll recognize it by shape and never read it again, and at that point all the anthropomorphized text is doing is taking up screen real estate that could have been used to display more errors.