IMHO it was all downhill once VLAN use became the default and viewed as equally secure as physically disparate networks. We used to physically isolate security

IMHO it was all downhill once VLAN use became the default and viewed as equally secure as physically disparate networks. We used to physically isolate security domains across the board. Everything is virtualized now, which makes it a whole lot less visible when boundaries are being violated, where it used to be obvious.