Timothy Pearson wrote:
LetsEncrypt does not appear to be secure enough as it
effectively requires automated certificate installation on the
master servers, and furthermore I expect it to be removed from
as a fully trusted root CA or at least demoted in some way in the
future [3].
I'd suggest a little more research while paying attention to the
originating source material (CA's who are losing money). At least one
of the FUD sources in your link has been responded to:
https://unmitigatedrisk.com/?p=552.