“Mythologized as rational and utility maximizing in economic theories, individuals' consumption habits are in reality motivated not just by personal needs for food, clothing, housing, and transport, but also by desires for novelty, status, social comparison, and respect.” O’Neill, Kriegler and Riahi (2014)
First of all, people, Rational Choice Theory is not a theory about human nature. It's an idealized model that helps economists and political scientists make hypotheses and predictions about group-level behavior.
The "rational" in Rational Choice Theory doesn't mean uninfluenced by "desires, novelty, status" or what have you. It means choosing actions that somehow help achieve goals (Branislav L. Slantchev). So if Jasper wants to impress Jason by treating him to a fancy restaurant and he succeeds in his goal, well then, that's evidence the fancy restaurant ploy was rational.
And utility is a measure of preferences and satisfaction - that's all! It doesn't imply a cold-blooded, robot-like calculation. As for "maximizing", that is also part of the model used to generate hypotheses and predictions when dealing with large data sets. The idea is that, all things being equal, people want to get the best value for the buck.
Reference:
O’Neill, B.C., Kriegler, E., Riahi, K. et al. A new scenario framework for climate change research: the concept of shared socioeconomic pathways Climatic Change (2014) 122: 387. doi:10.1007/s10584-013-0905-2