Actually, you don't always have to watch it for hours. Just setting a proper slow cool cycle does the trick. That old-school patience is still the right idea though.
Have you ever had a slow cool cycle fail on you? I've seen times when the temp doesn't drop evenly, and you get problems. That's why I still watch it, even with a timer set. Maybe it's too much, but I'd rather be careful.
Proper timers help a lot. But watching it sometimes catches those weird temp swings before they ruin a batch. Both methods together seem to work best for me.