Interesting topic; I made a thread about this subject awhile ago. Here is my take on it, if anybody cares -- Because of the stigma that SI holds with the rest of NYC, it seems that 50 held the attitude that SI nikkas were beneath him, so maybe that was part of the reason why Curly ignored GZA. On the other hand, he did diss Wu Tang earlier in his career, but I look at that different. The incentive for that had more to due with 50's tradition of "naming names", which was a gimmick he used to build buzz for POAD.
Let me explain, Woodface had no faith in his ability to draw an audience with his singles, and with no other option going for him beside his music, he made the decision to just start dissing dudes arbitrarily on record to cover up his self-perceived handicaps. This is what caused 50 to diss Wu Tang initially imo.
Personally, I don't fault 50 for taking such a risk, especially working under the constraints he had. It's not like 50 had other skill sets to fallback on. What I do fault woodface for is him not dealing with the consequences of his own actions. You initiated the investment while being fully aware of the risk, and when them boys on Guybrew came to collect on your risky investment by piercing your frame up with metal, you ran to the feds to bail yourself out. While claiming that your adversaries are the ones who are "fake".