If any one trend could be singled out, the general attrition theory is the one that holds the most weight IMO. That and the RICO Act have had far more impact on LCn as a whole than any one rat or informant.
IMHO the large number of rats is actually a symptom of the RICO effect, and not an independent factor in and of itself.
Valachi flipping didn't trigger a flood of made guys ratting; this phenomenon started in full force after RICO prosecutions were heavily implemented.
Italian-American assimilation and mainstreaming was what destroyed the smaller families IMHO. The RICO prosecutions just provided the coup de grace for what was already dying out. I also think (and I may be in the minority here) that some of the smaller families were centered on one strong personality, and when that person (such as, for example, Balistrieri) was out of the picture the family lost their cohesion that person's leadership and authority provided. This wouldn't be possible with the huge families in New York, obviously.
