While the evil-Internet, DMZ, walled-garden scheme might be flawed, I doubt it'll go away anytime soon.

- compute clusters / rendering farms: people pay for performance and aren't necessarily willing to sacrifice it for increased security (be it local firewall or SPECTRE mitigation) there

- engineering sub-divisions in large enterprises: its not unheard of that equipment in those is maintained by the engineers themselves (who are not necessarily well versed in network security matters and have other priorities) rather then the enterprise's IT team (this can coincide with the MS Windows / Unix schism)