At some point, searching for terms like "best hdtv 2013" would return a page full of sites with perfect urls like http://www.best-hdtv-2013.com/, and all of them would be extremely spammy and lacking in actual content. Seems less prevalent these days.
And the other thing is that we aren't really clicking on URLs, because it's just a string you cannot click on it. We are clicking on anchor texts and using ugly URLs as anchor text can be the problem. If the anchor text is a descriptive title then most (non-techie) users doesn't even see the URL before they click because they don't know it's displayed at the bottom of the browser if you move the mouse over them.
I'm not so sure of this. URLs that are over-optimised seem link-baity to me and I'm more inclined to not click it.