The first point to note, is that its all about legacy for both these fighters.
At first i thought it was a bad idea for both fighters to take this fight, because someone has to lose and they are both concerned about their legacies at this stage of their careers so why risk it? Someone's legacy will be tainted.
And then, after the GSP v Condit fight and seeing how Condit almost finished him with a head kick, i thought for sure Silva would find a chance to TKO St-Pierre because he is a bigger man and a faster & more accurate striker than Condit. So i thought this would be a bad fight for GSP to take.
But then i came to this thinking.
GSP mentioned 'he has other contenders to fight at 170'. But there will always be a new No1 contender, how long can he go on taking on No1 contenders until eg: someone like a Johnny Hendricks knocks him clean out?
Silva wont fight much longer, and he wont risk his legacy for many more years to come and against some young hungry fighter at MW will he?
History shows that when a champion loses the title, they normally dont get it back. There are of course some exceptions, Couture and GSP are two of them... but GSP already did this a few year ago against Serra, so why should they risk it?
We know that Silva wants this fight, and that GSP hasn't shown 'as much' enthusiasm, yes he said he wants to fight him, but we just dont know when this would be especially as White stated that GSP has asked for the Diaz fight next.
But if GSP takes this fight next and can beat Silva, he probably gets a 30+ million dollar pay day, completes his legacy, and if fought at MW becomes the only man in history to hold the WW title and MW title together, and would probably cement himself as the No1 p4p fighter in mma.
I think this is 'the risk' worth taking for Georges St-Pierre.