Interesting, I didn't know that. I still need some way to produce the verification files/tweets for my own account, though, and currently the only way to do that is with the client. (Maybe it works in the browser if you upload your key, I did not do that for the same reason the post author didn't.)
Additionally, I have used GPG and their website with javascript based crypto in some cases without using their NPM app. I believe their goal is to get other client implementations out there on the public api.