Comment by oberstein

I doubt Rich will ever push for it, but stranger things have happened. Types get in the way of data. When you ask a request "What's in you?" in Clojure you can just look at the data and find out. In Java you can ctrl+space in your IDE and look for public methods that by convention start with 'get', and then for the return values of those things also look for things that start with 'get', but that's a pretty impoverished way to get at the data. Try printing it out and you're likely to just get a memory address, great. So what do types buy you? Sometimes performance, but if that were always true then all static languages should be about as fast as C. The other thing is this "certainty" mentioned, and that certainty is just that you didn't make a typo or spelling error, woop-dee-doo, those are among the fewest sets of errors dynamic programming language users run in to, especially when you change your workflow to take advantage of the nature of dynamic languages, and a more valuable certainty is that this piece of data you have isn't going to change underneath you. You have to go all the way to Haskell (I'd argue Shen) to get real benefits of typing beyond performance and typo-protection, and most programmers are unwilling to do that for very good reasons.