Security certifications are one reason. OpenSSL maintains a module for FIPS compliance, which includes an entire boatload of weak and broken algorithms nobody else bothers with.
* they upgraded a major release (6.x to 7.x) in "stable" channel of their distro * their customers ran some ancient stuff that required those options.
We've failed a security audit because our checks just compared OpenSSH version ("if version is above this it doesn't need any change in config") while Red Hat's OpenSSH version was downgraded to earlier version settings/security issues