To tell you the truth legacy systems have been the bane of my career. The technology is outdated, limited, often restricted by surrounding legacy systems and then vulnerable security-wise. Often in my role I'll be tasked with figuring out and delivering a re-configuring, upgrade, migration of old applications, using old software running on outdated operating systems.
What often makes it worse is that the system you're looking at won't have any internal documentation about how it was setup. No worries, I'll Google a manual or the vendors documentation. This usually turns out to be either non-existent, outdated, limited to the point of being completely useless, or the wrong i.e. the documentation doesn't line up with what you're running.
This is usually only the beginning of the challenges you face dealing with legacy systems.
So, why. Why is it like this?