LE has saved us from spending many man hours of time updating certificates across all dev, staging, and live machines across all of our servers every year (which just so happens to be almost exactly the amount of time needed to forget some of the details of what needs to be done...).
But all that being said, when are we going to see a competitor pop up? Clearly what they are doing is working, so when are we gonna see some others attempt to do this? Having all your eggs in one basket is never a good thing in any part of life (no matter how perfect that basket is).
Having more than one "Let' Encrypt" would at the very least spread out some of the risk, and might even enable them to specialize a bit more (perhaps the competitor could target the issue of wildcard certs, or be somehow tailored for the use case of needing thousands of subdomains).
Has there been anyone else trying this?