I agree that Pit 85 is a decent target for most build. I don’t agree though with going past T1 being aspirational. Maybe Blizzard is saying that based on metrics they have but it seems to me that there are more players in T4 than in the lower Torments. I played 4 classes this season (no SB) and easily made it to T4 with all of them.
A game with replay value has difficulty levels so a player who completed the game on one difficulty level can move on to the next. D4 seasons would be extremely short for most if players stopped at T1.
By the way Pit 85 is T4.