> I am skeptical of the fact that even second generation seeds are that bad

Non-farmers really don't understand how human-engineered agriculture has been for the entire history of human civilization. For example, corn (maize) does not really exist in nature, it's a human-developed thing. Hybridized plants still carry the genetic code that allowed them to propagate through the ages before human agriculture, and these survival traits will very quickly express themselves in the offspring (seeds).