Trust is, by definition, an extention of solidity or support. CA is a trust model, which has proved both brittle and unworkable.
http://www.etymonline.com/index.php?term=trust&allowed_in_fr...
Google and other services presently provide extended trust and validity assessments for websites: pinned certificates, malware scans, and the like. A limited number of such reliable schemes would scale reasonably well, and should prove useful.
I'm not saying "perfect", I'm saying "useful".
I was thinking of something more akin to, say Google's pinned certificates (something which practices such as Let's Encrypt actually makes harder AFAICT):
https://security.stackexchange.com/questions/29988/what-is-c...
Or something that might be a parallel of email reputation services -- SenderBase / IronPort (now Cisco) rating email servers by their spam loads, etc.
Rather than negative reputation, a positive reputation (vouch rather than warn) might be viable. (Negative ratings systems, digital or otherwise, tend to inspire various legal assaults.)
For example, if users were responsible for knowing which fingerprints to trust for a given website, they would most likely just click "ok, trust it" for everything. Then, you're overall security goes way down because now people are conditioned to click "accept" to everything, regardless of the impact.