If singing/reality is what lets them win, then it make sense that they'd be less tolerant of drama, which is less of a safe win. If that's true, that is. A lot of reality shows flop, too.
The point is, being a safer network in terms of success doesnt make you more likely to take risks. It might teach you that taking risks doesnt pay, or is simply unnecesary since you can get by without risks just fine.
Lately, NBC has been taking the most risks of any network, because they are desperate to find somethng that works (and have Comcast to bankroll their risk taking.) ABC, which has also been struggling, has been taking some risks. Even the CW is trying to expand more into male-skewing shows, which is a risk for them. FOX and CBS, which are doing best, are taking the fewest risks.