We currently live in a society that valorizes meritocracy and equal opportunity and also providing for one's descendants. It supposes that you're you should have equal opportunity to enjoy a middle class or greater lifestyle if you're not a total mess, and that your success is something you can provide to your children as a leg up.

Not every society struggles/struggled so poignantly with the contradiction between those things as we now do, but we do, and that's where the modern criticism of nepotism originates.

Teaching your children your trade by inviting them into your workshop or boardroom is sensible, but it inevitably means that there's less room in that workshop or boardroom for the scrappy, bright outsider whose supposed to have a fair chance.

There's not really one right answer under that kind of tension, so there's no surprise when criticism is levied in either direction.