I guess another way to ask my question is - is the aforementioned sequence of steps (please add X, string of +1s, PRs welcome, etc) a bad thing?
IMO, building in the open is still the best way. But to ensure that you don't end up with a mongrel of a thing that tries to do every single thing requested by everybody, It does help to have a rigid set of goals about what we want to build. And the courage to say NO to feature requests that stray too far from the original design goals.
Then again you could develop a product behind doors despite the risk of building the wrong product ... :)
As every Hickey talk, I can only recommend watching the whole thing, it is not clojure-specific at all if that were off putting for you.