TF 904 Auto slipping 2nd to 3rd when manual shifting @ higher revs

Why do guys like to leave stuff disconnected or leave parts out of a trans just because somebody told them it was a smart idea? Is it because they're just lazy? I guess so. An automatic transmission clutch is NOT designed to slip; like a manual trans clutch. Slipping KILLS an automatic. It either wears down the frictions or scorches them so they just turn to mush. Compare a 904 clutch to a 727 one and lmk how much slipping it could take...