Many people looking for the "perfect language" want one that minimizes cognitive costs. An initial increase (comprehensive type systems like in MLs; rust's notion of ownership and lifetimes; Spark Ada's comingling of specification, code, and types) in cognitive cost which, once internalized, results in reduced cognitive costs for certain tasks. Less time spent developing tests. Less time debugging. Less time spent in maintenance (not because it's not needed, but because it goes faster when it's done).