How the hell did the Luddite Baku kick the Son'a off the planet in the first place? And why didn't the Son'a just move to another continent and build their own technologically advanced society to spite the Luddites? Hell, if the Son'a were competent, there wouldn't even be a movie.
They had the means to look at Data's positronic brain without much effort. They have the technology, stored somewhere perhaps.
And it's explained that the Son'a didn't want to live in the nebula (that no one else can enter without complications), they wanted to be part of the action. The Baku liked the place because it was protected by the nebula, the Son'a didn't. The Son'a only wanted the radiation. They wanted to have the cake and eat it too, so to speak.
Philosophies and intentions are not plot holes just because you don't agree with them.
And they still managed to build their own little empire all they lost was immortality, big deal.
And their infertility was their own fault. They didn't want to age, so they destroyed their bodies with genetic manipulation. And then they wanted to force the Baku off the planet.
All problems in this film are caused by the Son'a desperately pursuing eternal life, at all costs. First they destroyed themselves as a race with their genetic manipulation, then they wanted to harm the others in order to get that metaphasic radiation.