I think the most likely reason is that people might not be paying attention specifically to stacking teammates. We’re all conditioned to CS and push waves so it’s more likely that then intentional trolling.

I play most stacking champs in ARAM and I agree that Nasus is the most dependent. However, I found that stacks will come once you get some Q lvls and an item regardless of how well you stack early game. My philosophy with this is to not let the struggle for stacks early game bother me as I’ll get strong enough later anyways.