It is the case that Bryce is, ostensibly, just trying to help Ash fulfill their terminal goals while being healthier. The problem is that Bryce presumes that of the available action space, ice cream is fungible for something else that is healthier, and does not listen when Ash reasserts that ice cream itself is the thing they want.
Just because it is a safe bet that Ash will share the value/desire for good health does not mean Ash must prioritize good health in every action they take.
Right, those words definitely seem more accurate to me!