It does, but note https://github.com/CE-PhoenixCart/Phoen ... _3.php#L88
It only works when you can change it. If your web server is configured not to allow you to write files from a web page (which is actually the preferred configuration for security reasons), it won't work.
Renaming the admin folder is required when you can write files from the web server, because there are exploits that can take advantage of that. Those exploits don't work when you can't write from the web server. That's one way of preventing them. Renaming admin is another. Not being able to write files is superior but has the side effect of making the install unable to rename admin.
You can still rename admin if you want, but you'll need to manually rename the directory from something with sufficient permissions (FTP or the host's file manager) and then update the configuration file to match. Or allow writing before the install; install; and you can turn the permissions down again after.