In my experience thus far a top-shape battery is much less likely to die by the end of the day, even when limited to 80% charge. If I occasionally want or think I might need to charge to 100% I can while still preserving overall battery life for normal days (on which I usually only use 10-25% of the 80% charge).Are they teaching a behavior that is counterproductive? What good is a 100% capacity if we're not charging it past 80% anyway? Why not charge to 100% daily, reducing the risk of the battery dying by the end of the day, and after 2 years your capacity is down to 85%? Still more than limiting charging to 80%.
People have different needs and different priorities. But sorry my exercising basic freedom of choice bends you out of shape so severely.