With time we realised, that there was no systematic breeding to base this on. This is a typical example were the technology was not appropriate, because the starting point was not considered correctly. Additionally I found out, that farmers were more lacking good quality seeds than new genotypes. This means even the poorest farmer benefits from improved seeds without further input, as long as he is able to maintain them. I don't see why a farmer becomes more dependent when obtaining improved seeds, if these are adapted to his needs.
Farmers are the foremost experts on their own local needs and conditions.
If the new technology is unprofitable, they will be the first to throw it out. However, with respect to the other questions in the theme, Bt GMOs are not so simple, and it therefore is only natural that Bt transgenics should be such a prominent topic here. Their most important feature is they will accelerate Bt resistance, and in tropical areas with multiple generations of pests per year, resistance will develop quickly. The loss of Bt as a nondisruptive, nontoxic, highly selective insectide is a major loss for farmers and for society. By the same token, there are important issues surrounding GMOs that we have barely begun to explore, which in my opinion warrant the use of the precautionary principle.