I don't really buy the connection of past realignment (ACC poaching Big East in the early 00s, or the SWC collapse) to the modern realignment.
The ACC grabbed Boston College (not exactly a huge blow to the big east), Miami which was only in the big east for like a decade, and VT who was only a full big east member for a few years. The big east was never really a stable conference and its football membership largely transient. It was a relatively young conference.
The moves starting in ~2010 seemed different. Top, longstanding members being poached (or threatened to be, in the case of PAC looking at taking half the big 12), the big east actively ripped apart after they balked at ESPN's contract offer, etc. Conferences losing any geographical sense.