I agree there are many considerations when choosing a library, but conciseness does come up. For example, I was recently impressed with how concise http-kit is. The author seems proud of it too:
http://www.http-kit.org/http-kit-clean-small.html
You and I probably just have different values on this matter. Your comment implies that conciseness is merely "nice", so I'm guessing you just don't value that aspect of code as highly as I do.