Since I like to cheat at games frequently, I was reading a walkthrough for Simcity 4. Apparantly there's something the author calls the "peanut butter point" where things are going fine but there's no growth. The way to deal with such circumstances sounded eerily familiar:
A common phrase in comedy and the entertainment industry in general is "Leave your audience wanting more." Concentrate on what is RIGHT in your town... I hate saying this, but for the sims' own good, the best way to make your city get out of its sticky trap is to piss everyone off.