Warnings are already in place for outdated hardware. They're not going to playtest on a bare minimum PC because why would they?
Important effects aren't visible in a PC with low specs, for any game. Try playing a game below specs at low settings, you'll have missing textures and particle effects. Minimum setup means the game can run. OP needs settings at low, but if the devs were to turn on effects by default the minimum reqs would rise and OPs frames would drop. OPs hardware may be below minimum while running lowest settings.