[glass-]

I have no doubt that there would be incompetent or dishonest notaries. The difference being that in an alternative universe, where Convergence is used, a rogue notary doesn't destroy the trust of the entire system. When Symantec is a rogue notary, oh well, Mozilla and Google push out an update and no one uses Symantec anymore, their notary just becomes irrelevant. However, in this reality, the darkest timeline, deciding to stop trusting Symantec immediately breaks 30% of HTTPS websites on the internet, so even though Symantec has given everyone plenty of reasons to stop trusting them, we have no choice. Same for Comodo, their notary would have stopped being used in 2011 (after their root certificate compromise).

Instead, with Comodo and Symantec combined, we now have over 60% of HTTPS websites secured by authorities who are incompetent and/or dishonest.