Happy sims don't need to smile 100% all the time

Emotions are a sham in this game. TS4 Sims were never meant to have emotions or feelings, the player was meant to provide those.

It seems to me that EA has given up on the idea of providing Sims with believable emotions and reactions to stimuli. The proof is in the company's insistence (despite changing horses midstream on TS4) that the series must go the route of online multiplayer. That way, they officially don't have to keep up the pretense of simulating anything.