When you give them free rein, what do your sims choose to do?
Mine, in a well furnished house with plenty of fun items.. gather in the kitchen (usually in front of the sink) or in the bathroom and hold a 'mutual congradulation' party with the occasional dirty joke thrown in. Or if a child is present, they'll stand around him/her and shuffle over who gets to 'dance together' next. All this with the 'desperate need' tantrum between their turns.
I've occasionally let them go to see how far they would take it. I've had 4 of them pass out which left the last sim standing to stagger off to bed, several accidents, and in the case of the child trapped with the 'dance together', leave the mortal existance.
So, is this true of most sims or are mine just freaks in desperate need of micromanagement or some of Squinge's 'no autonomous' mods?