Today there are alternatives. Once upon a time those alternatives were either not written, not stable, or not free. Now it is just a matter of convincing an enormous number of developers to carefully rewrite large parts of their systems to use a different library instead of new features (or ironically, security fixes).
It was among the first at the time. OpenSSL was probably the dopest shit on the interwebz of crypto (or came close to it) at the time. Furthermore, these days it's too widely used so, everyone is just "fuck it." OpenSSL is the PHP of the cryptography world.
Also, I've see a ton of code just invoke the OpenSSL tool instead of actually use OpenSSL library.
I tried to use the library and was down in spirit, much like the author of the blog post, but I was too disappointed to even care, and just gave in to calling the tool from my code.
An idea: create a fork, call it OpenSSL2 and clean it up, but maintain both codebases, and end support for OpenSSL1 in 2-5 years?