This right here. Most of these systems are not new or not even from one vendor. Takovers and mergers create networks, that give most sys-admins nightmares. The

This right here. Most of these systems are not new or not even from one vendor. Takovers and mergers create networks, that give most sys-admins nightmares. The people who set these things up in the 50s or even 70s did not think about networking, let alone digital security. Most are retired. It would be extremely expensive to replace all infrastructure ad once, so most will be upgraded as we go along, creating new problems but also hopefully mitigating older bugs.