They could even add that in without math. Heavy bolter always treat Armor better than 4+ as a 4+ save. Armor 4+ or up gets no save.
Kinda rough on Terminators, no? -1 is not too bad though.. But many do not like modifiers?
It's up there on my list of annoying things in 8th like las guns being able to hurt land raiders, vehicles being monsterous creatures without need for facing or LOS from the weapon mounts(seriously breaks immersion, I still turn my dreadnoughts to face in game because it seems wrong otherwise) and loosing stable platform rules for dreads, terminators, bikes and aircraft.
I can absolutely understand that. But again playing the Devil´s Advocate - it put some balancing between monstrous creatures and vehicles. And stupid, kind of, stuff from older editions where Land Raiders could not split fire and you had glued the twin-linked lascannons at the back hatches and could only shoot one viable target per turn with the big, overcosted thing..
It is different, I have learned to live with the pros and cons.But some of the things bugs me too of course - no use flanking vehicles, but that is kinda mitigated that lasguns can, also wound them.. Even though it is stupid..