Seems like it was always heading this way, I don't think anyone really bought that the common use case for these style of quadruped robots would be walking around doing "safety inspections" in a warehouse.

Boston Dynamics' BigDog was funded by DARPA for the military. Was there anybody who actually believed the primary purpose for these things being developed wasn't military? I'm sure we'll find plenty of other uses for them in the future, but much like the internet or GPS, quadruped robots probably have a military origin in general.

Slaughterbot normalization in foreign wars is the first step towards normalizing it domestically

Foucault's boomerang (aka the Imperial boomerang): https://en.m.wikipedia.org/wiki/Imperial_boomerang

Life imitates art. Many Hollywood films have already depicted this scenario.