I can see where WeightPSHR is coming from. The higher the risk, the better the reward.
GSP is playing it safe by beating opponents through attacking their weaknesses. This will almost certainly guarantee that he beats any 170 pounder that they put in front of him, but doesn't always make for the most exciting fights.
If he were to attempt to finish more fights in a spectacular fashion, he runs the risk of losing it all like he did to Serra, but he also stands to gain more popularity, PPVs, money, etc.
If it were me, I'd keep winning and not take the risk.