Rich Hickey stands for good design. That means saying "no" to a lot if ideas that are good, but not part of the vision, and it means not running experiments on your users in the main releases. Whether he reaches that ideal, I dunno, but he lays out the vision pretty clearly when he speaks. It isn't the only way, but it is Clojure's way.

When he talks about customers and stakeholders, he is talking about people who have bought in to that design. It is very easy to support his position here. Rich knows exactly how he wants to program and the man is a visionary of data-driven programming and thinking. If you don't like that vision, maybe don't use Clojure and find a different lisp.

Great design is a very foreign idea to a lot of mainstream software developers - most of them, sooner or later, go for the "big rewrite" because they didn't get the design right to start with. Things like Python 2 -> 3 spring to mind (breaking changes to print! whoever thought that was a good idea didn't respect the language users). With that rational, he is promising not to do exactly what the Python people did.