After reading Ferreira & Patson (2007)

If a constraint, such as bounded rationality or limited memory, can be used as an explanatory factor for some behavior, you kill two birds with one stone. On the one hand, you make a weaker assumption about the potential of the object of modelling, and on the other hand, you explain more of its behavior. An important agenda for the cognitive sciences is to find out the boundaries of cognition, and use them to explain behavior.