This will still require early stage overhead for many people switching over / 'going dark all the things'. Even though Let's Encrypt's goal is to make the process of encrypting the Transport Layer seamless, ubiquitous and non-commercial.

Take for example my setup. It sits on a private NGINX server, and is proxied through a public facing CDN. Trying to simply 'switch on' TLS involves absorbing academic style tutorials from multiple disparate sources, and requires me to have a background in DevOps and that I have at least tried some technical task like this before. In layman's terms: Unnecessary Early Stage Overhead.

Now give Let's Encrypt a few more years and it will be a lot more seamless; possibly the default. It could possibly be 'baked in' to things like Softaculous, and cPanel, which are brilliant drivers for the success of web software. Digital Ocean staff are probably already working on a droplet with LetsEncrypt baked in...