Earlier quoted context omitted.
> If HTTP referrers never existed, the web would still be huge and would still be full of amazing content. While we're at it, let's get rid of User-Agent. No sarcasm intended, I'm serious. It only does bad things.
I disagree - it's nice to be able to serve a mobile layout to a mobile device. If I'm trying to load, say, CNN or ESPN on an older mobile phone, I don't need all the cruft that comes with the desktop version. (We can get into all the evils suggested by http://xkcd.com/869/ , but for the purposes of this argument I'm assuming that web developers and sysadmins are competent and not evil.)
Now, just for fun and laughs, check out what user-agent string is sent by Chrome. I guess Google assumes everyone is like them and their poor browser would get blocked if they just said it's a Chrome.
1. https://groups.google.com/a/googleproductforums.com/d/topic/...