As a StartSSL customer, I've just had the email in my inbox telling me all about this.
I know people don't like them, but before LetsEncrypt, StartSSL were one of the few providers of basic certs that were free. All I needed for my home setup was a cert for my Exchange server, and they've been providing me one for about 5 years now, and I've never had a problem, and every client trusted it[1]. Granted, their website is a bit weird, but once you work it out, it's fairly easy to renew a free cert.
Obviously, next renewal I'll be jumping ship to LetsEncrypt (now that the ACME clients for Windows have matured), so I am left struggling to see what benefit StartEcrypt has over LetsEncrypt.
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[1] Coincidently, BB10 on Blackberrys does not trust the CA chain for LetsEncrypt certs, and it's unlikely Blackberry will ever fix this.