I never once had a bug resulting from the use of C#'s var in 10 years of dev work. Not once.

And I disagree with OP's notion that adding var to Java is at the expense of the reader. There is no expense, var improves code readability dramatically.

These sound like arguments Java devs came up with through cognitive dissonance to hold on to the notion that Java's language features are superior to C#'s, they are not.

No, no need for the straw man attack. I don't think they're superior, but there already is "one way" to do it in Java, and it should stay that way to avoid creating a mess. Whether or not it is superior is likely a very subjective debate that I could argue both ways in.